The UN has unanimously voted to adopt a binding resolution on ridding Syria of chemical weapons.
At a session in New York, the 15-member Security Council backed the draft document agreed earlier by Russia and the US.
The deal breaks a two-and-a-half year deadlock in the UN over Syria, where fighting between government forces and rebels rages on.
The vote came after the international chemical watchdog agreed on a plan to destroy Syria’s stockpile by mid-2014.
Speaking after the vote in New York, UN Secretary General Ban Ki-moon described the decision as “historic”.
“Tonight the international community has delivered.”
Ban Ki-moon urged the Syrian government to implement the resolution “faithfully and without delay”, and also announced a tentative date of mid-November for a new peace conference in Geneva.
US Secretary of State John Kerry said the UN demonstrated that “diplomacy can be so powerful that it can peacefully defuse the worst weapons of war”.
John Kerry said the resolution would for the first time seek to eliminate entirely a nation’s chemical weapons capability.
Russian Foreign Minister Sergei Lavrov also hailed the move, saying Moscow “war ready to take part in all operations” in Syria.
The UN has unanimously voted to adopt a binding resolution on ridding Syria of chemical weapons
However, he stressed that the success of international efforts was “not only on Damascus’ shoulders” and that Syrian opposition must co-operate.
The UN resolution condemns the use of chemical weapons but does not attribute blame.
The text has two legally binding demands: that Syria abandons its weapons stockpile and that the chemical weapons experts be given unfettered access.
Although the draft refers to Chapter VII of the UN Charter, which allows the use of military force, a second resolution authorizing such a move would be needed.
President Barack Obama earlier said agreement on the issue by council members would be a “potentially huge victory for the international community”.
Previous attempts at a resolution stumbled amid disagreements between Russia and the US on how to deal with the crisis in Syria.
The US – backed by France and the UK – had pushed for a resolution carrying the threat of military action against Syrian President Bashar al-Assad’s armed forces. Russia had opposed this.
Reacting to the vote, Syria’s UN Ambassador Bashar Jaafari said the resolution covered most of Damascus’ concerns.
But he stressed that countries supporting Syrian rebels should also abide by the adopted document.
The UN vote came just hours after the Organization for the Prohibition of Chemical Weapons (OPCW) adopted what it called “a historic decision on the destruction of Syria’s chemical weapons”.
In a statement after a late-night meeting in The Hague, the watchdog said its executive council “agreed on an accelerated programme for achieving the complete elimination of Syria’s chemical weapons by mid-2014. The decision requires inspections in Syria to commence from 1 October 2013”.
“The decision also calls for ambitious milestones for destruction which will be set by the (executive) council by 15 November.”
OPCW Director General Ahmet Uzumcu said the move “sends an unmistakable message that the international community is coming together to work for peace in Syria”.
Syria has submitted details of its chemical weapons as part of a US-Russia brokered deal to make them safe, the chemical arms watchdog has said.
The Hague-based OPCW added that it expected more details from Syria in the coming days and had postponed a meeting planned for Sunday.
Syria was given a Saturday deadline to give a full list of its chemical arms.
The US had threatened military action over a chemical attack in Damascus last month, which the UN called a war crime.
The US, UK and France have accused Syrian government forces of carrying out the attack in the Ghouta district on August 21, but President Bashar al-Assad has blamed rebel groups.
Separately, two Syrian rebel groups have agreed a ceasefire in the northern town of Azaz after two days of fighting that raised fears of a war within a war.
Michael Luhan, a spokesman for the Organization for the Prohibition of Chemical Weapons (OPCW), which is responsible for policing the treaty outlawing chemical arms, said Syria’s submission was an “initial declaration”.
Syria has submitted details of its chemical weapons as part of a US-Russia brokered deal to make them safe
He said it was now being examined by the organization’s technical secretariat but he declined to say what was in it.
A UN diplomat confirmed to Reuters that details had been submitted, adding: “It’s quite long… and being translated.”
The US-Russia-brokered deal aims to have inspectors on the ground in Syria in November, when they will make an initial assessment and oversee the destruction of certain equipment.
The destruction of all of Syria’s chemical weapons would then be completed by mid-2014.
The core members of the OPCW were expected to vote on the timetable next week.
However, the OPCW said in a statement on Friday that a meeting of its executive council scheduled for Sunday had been postponed, without giving a reason.
“We will announce the new date and time… as soon as possible,” it said.
Once the OPCW agrees to the plan, the UN Security Council will seek to endorse it.
However, the five permanent members are still discussing the wording of a resolution, with Russia opposing threats of force against Syria.
On Monday, the UN confirmed in a report that the nerve agent sarin had been used in a rocket attack in Ghouta, although it did not apportion blame.
Secretary General Ban Ki-moon said the mission was unable to verify the number of casualties, but referred to the “terrible loss of life on August 21”.
France, the UK and US insist the report clearly backed their stance that only the government forces were capable of carrying out the attack.
Syria’s ally, Russia, rejected the argument, saying it had “serious grounds” to believe the attack had been a provocation by rebel forces.
Two rival Syrian rebel groups in the northern town of Azaz have agreed a ceasefire.
The Islamic State in Iraq and Syria (ISIS), linked to al-Qaeda, seized the town on Wednesday from the larger Western-backed Free Syrian Army (FSA).
Fighting between rebel groups has raised fears of a war within a war.
The clashes come ahead of a deadline, on Saturday, for Syria to provide a list of its chemical weapons facilities as part of a US-Russian deal for the country to destroy its deadly arsenal.
Russia’s Deputy Foreign Minister, Sergei Ryabkov, is currently holding talks in Damascus about the deal.
But the agreement still faces many hurdles – including the differing opinions of the US and Russia.
US Secretary of State John Kerry said a “definitive” UN report had proved that the Syrian government was behind a deadly chemical weapons attack in the Damascus suburbs of Ghouta on August 21.
But Damascus – backed by Moscow – insists that rebel forces carried out the attack.
The West also wants any UN resolution on Syria’s chemical weapons to include the threat of military force in the result of non-compliance – but Russia objects to any mention of this.
Syria’s President Bashar al-Assad, in an interview with Fox News, said it could take about a year to destroy Syria’s chemical stockpiles and could cost about $1 billion.
Under the ceasefire deal in Azaz the two rebel sides have agreed to exchange prisoners and hand back property.
Two rival Syrian rebel groups in the northern town of Azaz have agreed a ceasefire
It is unclear whether the ceasefire will have an impact on clashes between the groups elsewhere in the country.
Analysts say there is more chance that the US and other Western powers may arm the Free Syrian Army if it shows a distinct separation from the Islamists.
The fighting in Azaz began when a wounded rebel – either from ISIS or from an allied group, al-Muhajireen – was taken to a field clinic and, while there, he was filmed as part of a fundraising exercise.
The wounded fighter demanded the film, and called some of his friends to come and help him.
Free Syrian Army (FSA) rebels from a unit called the Northern Storm brigade were guarding the field clinic, and there was a confrontation which ended up with ISIS launching a full attack on the town, pushing out the Northern Storm brigade.
ISIS is reported to have made a number of arrests of activists, journalists and even Sharia court officials during the time it controlled Azaz.
One eyewitness inside the town said no-one was smoking on the streets – tobacco is forbidden according to strict Islamist doctrine.
While the Azaz violence seems to have been the result of a particular set of circumstances rather than a long-planned offensive, our correspondent says there is a record of skirmishes between the Jihadis and FSA brigades for control of the border crossings into Turkey.
Meanwhile, the party of Syria’s Deputy Prime Minister Qadri Jamil insists he was misquoted in Friday’s edition of the UK’s Guardian newspaper.
Qadri Jamil reportedly told the paper that the civil war had reached stalemate, with neither government forces nor the rebels strong enough to win – and that the government would use proposed talks in Geneva to call for a ceasefire.
But the People’s Will Party said the Guardian journalist was ”neither precise nor professional” about what he quoted Qadri Jamil as saying.
Iranian President Hassan Rouhani has said Tehran is ready to help broker peace in Syria, as part of what he called his country’s “constructive engagement” policy with other nations.
In an article in the Washington Post newspaper, Hassan Rouhani wrote: “We must create an atmosphere where peoples of the region can decide their own fates.”
Correspondents say the article is the latest signal that Hassan Rouhani wants to improve Iran’s relationship with the US and other countries that believe Iran is developing nuclear weapons.
Syrian leader Bashar al-Assad has said he is committed to a plan to destroy his country’s chemical weapons but warned it could take about a year.
Speaking to Fox News,Bashar al-Assad again denied claims that his forces were responsible for a deadly chemical attack near Damascus on August 21.
The Syria disarmament plan was unveiled by the US and Russia last weekend.
The West wants the deal enshrined in a UN resolution backed by the threat of military force, but Russia objects.
Damascus – backed by Moscow – has insisted that rebel forces carried out last month’s attack in the Ghouta area.
In a separate development, fierce fighting has been reported between two rebel groups in the north of Syria.
Activists said the fighting began when jihadists from the al-Qaeda-linked group, the Islamic State of Iraq and the Levant (ISIS), and fighters from the Western-backed Free Syrian Army (FSA) clashed in the town of Azaz, near the Turkish border.
This is believed to be one of the biggest confrontations so far between the jihadists and the FSA.
Referring to the issue of destroying Syria’s stockpiles of chemical weapons, Bashar al-Assad said it was “a very complicated operation, technically”.
“And it needs a lot of money, some estimates about a billion.
“So it depends, you have to ask the experts what they mean by quickly. It has a certain schedule. It needs a year, or maybe a little bit more.”
Bashar al-Assad has said he is committed to a plan to destroy his country’s chemical weapons but warned it could take about a year
And when asked whether he would be willing to hand over chemical weapons to the US, President Bashar al-Assad said: “It needs about one billion. It is very detrimental to the environment. If the American administration is ready to pay this money and take the responsibility of bringing toxic materials to the United States, why don’t they do it?”
Bashar al-Assad also used the one-hour interview recorded in Damascus to criticize the US stance in the Syrian crisis.
Unlike the Russians, he said, Washington had tried to get involved in Syria’s leadership and governance.
Bashar al-Assad argued that if there was mutual respect, there would not be any problems.
“Listen to your people. Follow the common sense of your people,” he said, in an apparent reference to US President Barack Obama.
Bashar al-Assad’s comments come shortly after a senior Russian diplomat said Damascus would fulfill its commitment to eliminate its chemical weapons by mid-2014.
After talks in Syria on Wednesday, Deputy Foreign Minister Sergei Ryabkov said Bashar al-Assad was “very serious” about the disarmament plan.
Sergei Ryabkov also said that Syrian officials had handed him “material evidence” that showed the rebels were involved in the sarin attack last month, contradicting claims by the US that the regime was responsible.
And the Russian diplomat criticized the United Nations for being “one-sided” in its recent report on the attack – a claim the UN denied.
The report – prepared for UN weapons experts after a visit to Syria – did not apportion blame for the August 21 attack.
Meanwhile Germany’s Chancellor Angela Merkel has said in an interview on German television that chemicals exported to Syria which were capable of being used to make poison gas were used for civilian purposes.
The German government, responding to a request from a member of parliament, said 137 tonnes of two substances capable of being used to make the poison gas, Sarin, were exported to Syria between 2002 and 2006.
Angela Merkel added that officials were still trying to ascertain what use was made of chemicals exported after 2006 and before May 2011, when Germany imposed strict controls on exports to Syria.
More than 100,000 people have been killed since Syria’s civil war began in early 2011, according to the UN.
Millions of Syrians have fled the country and millions more have been left homeless.
A UN report has confirmed “unequivocally and objectively” that chemical weapons have been used in Syria.
The report says sarin gas was used in a rocket attack in the Syrian capital, Damascus, last month, although it has not attributed blame.
“This is a war crime,” Secretary-General Ban Ki-moon said.
US allegations that the government was responsible led to threats of military action and then a US-Russia deal for Syria to make safe its chemical arms.
World powers will now try to hammer out a UN Security Council resolution.
Earlier, UN investigators said they were probing 14 alleged chemical attacks in Syria since September 2011.
Meanwhile, Turkey said it had shot down a Syrian helicopter close to its border. Deputy PM Bulent Arinc said the aircraft was engaged by fighter jets after violating Turkish air space.
Ban Ki-moon has been briefing the Security Council on the report, and is then expected to address the media.
He said he was submitting the UN mission’s report “with a heavy heart”.
“The mission has concluded that chemical weapons were used on a relatively large scale in the Ghouta area of Damascus [on 21 August]… The attack resulted in numerous casualties, particularly among civilians.”
Ban Ki-moon spoke of the suffering of the victims.
UN report confirms sarin gas was used in a rocket attack in Damascus last month
“Survivors reported that following an attack with shelling, they quickly experienced a range of symptoms, including shortness of breath, disorientation, eye irritation, blurred vision, nausea, vomiting and general weakness.
“Many eventually lost consciousness. First responders described seeing a large number of individuals lying on the ground, many of them dead or unconscious.”
The UN investigators examined many samples from the scene.
Ban Ki-moon said: “On the basis of its analysis, the mission concluded that it – and I quote – <<collected clear and convincing evidence that surface-to-surface rockets containing the nerve agent sarin were used in the Ein Tarma, Moadamiyah and Zalmalka in the Ghouta area of Damascus>>.”
Ban Ki-moon added: “I trust all can join me in condemning this despicable crime. The international community has a responsibility to hold the perpetrators accountable.”
He said the mission was unable to verify the number of casualties, but referred to the “terrible loss of life on 21 August”.
He added: “This is the most significant confirmed use of chemical weapons against civilians since Saddam Hussein used them in Halabja in 1988.”
Assigning blame for the attack in Ghouta was not part of the inspectors’ remit.
However, diplomats have suggested the way the facts are reported may point to the Syrian government as the perpetrators.
Syrian President Bashar al-Assad has denied allegations his government was behind the attack, instead blaming the rebels.
Earlier, Paulo Pinheiro, the chairman of the UN Commission of Inquiry on Syria, said the commission had been investigating 14 alleged chemical attacks since it began monitoring Syrian human rights abuses in September 2011.
Paulo Pinheiro said investigators had not so far been able to assign blame and were awaiting details from Monday’s UN report.
He said the commission believed both President Assad’s government and the rebels were responsible for war crimes, but that the regime alone had perpetrated crimes against humanity.
War crimes, including mass executions, rape and torture, were continuing, the commission said.
Its investigators said a referral to the International Criminal Court was imperative.
French President Francois Hollande and his Foreign Minister Laurent Fabius earlier met British Foreign Secretary William Hague and US Secretary of State John Kerry in Paris on Monday to discuss the Syrian crisis.
The UN Security Council is expected to draft a resolution in the coming days.
President Barack Obama says he will pursue diplomatic efforts to remove Syria’s chemical weapons but has ordered the US military to “be in a position to respond” if such measures fail.
In a televised address, Barack Obama said he had asked Congress to postpone a vote authorizing the use of force.
The US has threatened air strikes after a chemical weapons attack killed hundreds in Damascus last month.
Russia has proposed such weapons be placed under international control.
Although Syrian officials have agreed in principle, the US and its allies remain skeptical.
The Russian plan triggered a day of diplomatic wrangling at the UN on Tuesday.
Speaking from the White House, President Barack Obama said his administration had long resisted calls for military action in Syria because he did not believe that force could solve the civil war.
But he said he changed his mind after the chemical weapons attack in the Damascus suburbs on August 21.
“The images from this massacre are sickening,” he said.
“On that terrible night, the world saw in gruesome detail the terrible nature of chemical weapons and why the overwhelming majority of humanity has declared them off limits, a crime against humanity and a violation of the laws of war.”
The Syrian government has strongly denied carrying out the attack and instead blamed rebels trying to oust President Bashar al-Assad.
However, Barack Obama said the US “knew” the Assad regime was to blame.
Barack Obama says he will pursue diplomatic efforts to remove Syria’s chemical weapons
“We know that Assad’s chemical weapons personnel prepared for an attack near an area where they mix sarin gas,” he said.
“They distributed gas masks to their troops. Then they fired rockets from a regime-controlled area into 11 neighborhoods that the regime has been trying to wipe clear of opposition forces.”
Barack Obama said that such an attack was not only a violation of international law it was also a danger to US national security.
“As the ban against these weapons erodes, other tyrants will have no reason to think twice about acquiring poison gas and using them,” he said.
He said that “after careful deliberation” he had decided to respond to the use of chemical weapons through “a targeted military strike”.
“The purpose of this strike would be to deter Assad from using chemical weapons, to degrade his regime’s ability to use them and to make clear to the world that we will not tolerate their use. That’s my judgment as commander in chief.”
However, Barack Obama said he would not “put American boots on the ground in Syria” or pursue open-ended action such as that in Iraq or Afghanistan.
He added: “Others have asked whether it’s worth acting if we don’t take out Assad. As some members of Congress have said, there’s no point in simply doing a pinprick strike in Syria. Let me make something clear: The United States military doesn’t do pinpricks.”
President Barack Obama said he welcomed Russia’s proposal as an alternative to military action, but added: “It’s too early to tell whether this offer will succeed.
“Any agreement must verify that the Assad regime keeps its commitments. But this initiative has the potential to remove the threat of chemical weapons without the use of force.”
Barack Obama said he had therefore asked the leaders of Congress to postpone a vote to authorize the use of force “while we pursue this diplomatic path”.
He confirmed earlier reports that US Secretary of State John Kerry would meet his Russian counterpart Sergei Lavrov in Geneva on Thursday, adding: “I will continue my own discussions with President [Vladimir] Putin.”
“I’ve spoken to the leaders of two of our closest allies, France and the United Kingdom. And we will work together in consultation with Russia and China to put forward a resolution at the UN Security Council requiring Assad to give up his chemical weapons and to ultimately destroy them under international control.”
He added: “Meanwhile, I’ve ordered our military to maintain their current posture, to keep the pressure on Assad and to be in a position to respond if diplomacy fails.”
David Petraeus is urging members of Congress to support President Barack Obama’s plan for military intervention in Syria.
Syrian President Bashar al-Assad is suspected of launching chemical attacks on his own people, killing more than 1,400, including hundreds of children.
Former CIA director and retired Army General David Petraeus says military action in Syria is “necessary” to deter other nations – like Iran and North Korea – from using similar weapons.
While President Barack Obama could have used military force in Syria without the approval of Congress, he opted to put the decision to a vote. Even if Congress doesn’t approve the president’s plan – which seems likely given the bi-partisan objections to intervening in yet another war in the Middle East – Barack Obama still has the authority to launch an attack.
“Failure of Congress to approve the president’s request would have serious ramifications not just in the Mideast but around the world,” David Petraeus said in a statement to POLITICO.
President Barack Obama is using gruesome footage that shows the carnage in the suburbs of Demascus following the August 21, attack, when the White House alleges Bashar al-Assad launched sarin gas in areas considered to be rebel strongholds.
David Petraeus is urging members of Congress to support President Barack Obama’s plan for military intervention in Syria
In one of the more heartbreaking videos, a room is full of what appear to be the lifeless bodies of dozens of children. In another, men are seen foaming at the mouth and having convulsions.
In all, 1,429 people were killed in the vicious attack, including at least 426 children.
David Petraeus, who is widely respected amongst lawmakers when it comes to military matters, could help persuade members of Congress to support the White House’s plan for Syria.
“Military action against the Syrian regime is, thus, necessary not just to deter future use of chemical weapons in Syria and elsewhere, but also to ensure that Iran, North Korea and other would-be aggressors never underestimate the United States’ resolve to take necessary military action when other tools prove insufficient,” David Petraeus said in the statement.
David Petraeus served as the U.S. commander for the wars in Iraq and Afghanistan under former President George W. Bush and President Barack Obama. He was tapped by Barack Obama to be the director of the CIA in 2011 but was forced to resign after an affair he had with his biographer went public.
Former Secretary of State Hillary Clinton and former Secretary of Defense Robert Gates also have publicly supported the president’s call for military intervention in Syria.
On Monday – when Congress is back in session – President Barack Obama will sit for interviews with six different television networks in an attempt to win public support for his plan for Syria. The interviews will be conducted by ABC’s Diane Sawyer, CBS’s Scott Pelley, CNN’s Wolf Blitzer, Fox’s Chris Wallace, NBC’s Brian Williams and PBS’s Gwen Ifill.
Congress is expected to vote on the matter later this week, as support for Barack Obama’s plan continues to dwindle.
President Barack Obama last week canceled a trip to California so he could stay in Washington to continue lobbying for intervention in Syria. The president was scheduled to attend a $324,000 a plate fundraiser at the home of Marta Kauffman, the co-creator of the NBC sitcom Friends.
Vice-President Joe Biden has said the US has “no doubt” that the Syrian government has used chemical weapons and that it must be held accountable.
The US has said its military is ready to launch strikes if President Barack Obama order an attack, and allies say they too are ready to act.
The Syrian government has strongly denied claims it used chemical weapons.
UN weapons inspectors are set to return to the site of last week’s suspected attack near Damascus on Wednesday.
Their evidence-gathering visit was delayed by a day after they were fired on.
The US says it will release its own intelligence report into the incident at Ghouta, a suburb of the capital, in the coming days.
More than 300 people reportedly died there.
President Barack Obama is said to have made at least 88 calls to foreign leaders since Wednesday’s suspected attack.
Vice-President Joe Biden has said the US has “no doubt” that the Syrian government has used chemical weapons and that it must be held accountable
British PM David Cameron said the world could “not stand idly by”, and French President Francois Hollande said France was “ready to punish” whoever was behind the attack.
On Wednesday, Russian Foreign Minister Sergei Lavrov warned that “attempts at a military solution will lead only to the further destabilization” in Syria and the region.
Sergei Lavrov emphasised the need for a political solution in a phone call to the joint UN-Arab League envoy to Syria, Lakhdar Brahimi, the foreign ministry in Moscow said.
Russia, China and Iran have previously warned against launching an attack on the war-ravaged country, where more than 100,000 people are thought to have died in two years of fighting.
Stocks have fallen on global markets and oil prices have shot up amid growing concern about an impending attack.
The US has not yet released its intelligence report into the alleged chemical attack, but US officials now say they are certain the Syrian government was behind the incident.
Joe Biden is the most senior member of the Obama administration to blame the Syrian government for the attack.
In a speech to a veterans’ group in Houston, he said there was “no doubt who was responsible for this heinous use of chemical weapons in Syria: the Syrian regime”.
He said that “those who use chemical weapons against defenceless men, women, and children… must be held accountable”.
White House spokesman Jay Carney earlier said it would be “fanciful” to think anyone else could be responsible – saying the Syrian regime remained in control of the country’s chemical arsenal and used the type of rocket that carried the payload used last Wednesday.
But he insisted there were no plans for “regime change”. Any military campaign is likely to be limited in scope, with missile strikes targeting military sites and no ground troops.
Medecins Sans Frontieres reports hospitals it supports in Syria treated about 3,600 patients with “neurotoxic symptoms”, of whom 355 have died.
MSF said the patients had arrived in three hospitals in the Damascus governorate on August 21 – when opposition activists say chemical attacks were launched against rebels.
But MSF says it cannot “scientifically confirm” the use of chemical weapons.
Both sides in the conflict accuse each other of using them.
MSF says staff at the hospitals described a large number of patients arriving in the space of less than three hours with symptoms including convulsions, extreme salivation, contracted pupils and sight and respiratory problems.
The charity said many were treated with atropine, a drug administered to those with “neurotoxic symptoms”.
Medecins Sans Frontieres reports hospitals it supports in Syria treated about 3,600 patients with neurotoxic symptoms
“MSF can neither scientifically confirm the cause of these symptoms nor establish who is responsible for the attack,” said MSF Director of Operations Bart Janssens.
“However, the reported symptoms of the patients, in addition to the epidemiological pattern of the events, characterized by the massive influx of patients in a short period of time, the origin of the patients, and the contamination of medical and first aid workers, strongly indicate mass exposure to a neurotoxic agent.
“This would constitute a violation of international humanitarian law, which absolutely prohibits the use of chemical and biological weapons.”
The opposition Syrian Observatory for Human Rights has given its latest assessment of the number of casualties from the alleged attacks.
The British-based group said it estimated that 322 had died, 54 of them children.
In the immediate aftermath, casualty figures varied widely with opposition activists saying between several hundred and more than 1,000 had been killed.
MSF’s disclosure adds to mounting allegations that chemical weapons were used in suburbs to the east of Damascus and in an area to the south-west on August 21.
Unverified video footage posted soon afterwards shows civilians, many of them children, dead or suffering from what appear to be horrific symptoms consistent with a chemical attack.
Rebels and opposition activists accuse forces loyal to President Bashar al-Assad of carrying out such attacks.
But state TV accuses the rebels, saying barrels of chemical weapons were found as troops entered previously rebel-held districts.
Soldiers had “suffocated” as they tried to enter Jobar, one of the towns in the Ghouta district around Damascus.
President Barack Obama has said the alleged use of chemical weapons in Syria in an attack on Wednesday is a “big event of grave concern”.
Barack Obama said the US was still seeking confirmation such weapons were used, but if proved true the situation would “require America’s attention”.
Meanwhile, Syria’s main ally Russia has said there is growing evidence that rebels were behind the attack.
The opposition says hundreds died in a government assault outside Damascus.
But despite calls from many different countries, there is no sign yet that the Syrian authorities will allow a UN inspection team to visit to investigate the claims.
Unverified footage shows civilians – many of them children – dead or suffering from what appear to be horrific symptoms as a result of Wednesday’s attack.
Also on Friday, UN agencies said the number of children forced to flee Syria had reached one million.
The UN’s refugee agency, UNHCR, and children’s fund, Unicef, described the figure as “a shameful milestone”, and said a further two million children were displaced within the country.
Last year, President Barack Obama said the use of chemical weapons in Syria would cross a “red line” and force a tough US response.
Meanwhile, Russia joined calls for an “objective investigation” by UN chemical weapons experts.
Foreign Ministry spokesman Aleksandr Lukashevich said Moscow had urged President Bashar al-Assad to co-operate with a probe, but also that questions remained about the willingness of the opposition to provide “secure, safe access of the [UN] mission to the location of the incident”.
“More new evidence is starting to emerge that this criminal act was clearly provocative,” the ministry added.
President Barack Obama said the US was seeking confirmation if chemical weapons were used in Damascus attacks
“On the internet, in particular, reports are circulating that news of the incident carrying accusations against government troops was published several hours before the so-called attack. So, this was a pre-planned action.”
The ministry also described as “unacceptable” calls from various European capitals for the UN Security Council to authorize the use of force in Syria.
Other leaders have also pushed for an urgent UN inquiry.
A spokesman for UN Secretary General Ban Ki-Moon said he was “giving his utmost attention to the tragic situation” and intended to conduct a “thorough, impartial and prompt investigation”.
The UN High Representative for Disarmament Affairs, Angela Kane, will travel to Damascus on Saturday to push for access for the UN inspectors.
“It is of paramount importance that all those who share the concern and urgency of investigating these allegations, equally share the responsibility of co-operating in generating a safe environment for the [UN] mission to do its job,” Ban Ki-Moon’s spokesman added.
Damascus has described the allegations that it sanctioned the use of chemical weapons as “illogical and fabricated”.
The main opposition alliance, the National Coalition, has meanwhile said that it will do everything to assist the UN inspectors and ensure their safety.
“It is critical that those inspectors get there within 48 hours. The clock is ticking and we want to see those inspectors and we believe that the evidence will show who used those chemical weapons against innocent civilians,” spokesman Khaled Saleh told the Reuters news agency.
Opposition activists are also reportedly trying to smuggle tissue samples from victims’ bodies to the UN inspectors to prove their claims.
“The UN team spoke with us and since then we prepared samples of hair, skin and blood and smuggled them back into Damascus with trusted couriers,” activist Abu Nidal told Reuters.
The White House said today that Syrian forces under President Bashar al-Assad have used chemical weapons “on a small scale” against the opposition rebels.
A senior aide to President Barack Obama said the US estimated 100-150 people had died in “multiple” attacks.
Ben Rhodes said the US president had decided to provide unspecified “military support” to the opposition.
The White House had previously warned that the US considers the use of such weapons crossing a “red line”.
Ben Rhodes, a deputy national security adviser to Barack Obama, said the US had no “reliable” evidence the opposition had used chemical weapons.
Earlier, the United Nations said the number of those killed in the Syrian conflict had risen to more than 93,000 people.
Ben Rhodes said the president had made the decision to increase assistance, including “military support”, to the opposition’s Supreme Military Council (SMC).
He declined to provide further details, other than to say it would be “different in scope and scale to what we have provided before”.
Syrian forces under President Bashar al-Assad have used chemical weapons on a small scale against the opposition rebels
“The president has been clear that the use of chemical weapons – or the transfer of chemical weapons to terrorist groups – is a red line for the US,” Ben Rhodes said.
“Our intelligence community now has a high confidence assessment that chemical weapons have been used on a small scale by the Assad regime in Syria. The president has said that the use of chemical weapons would change his calculus, and it has.”
Ben Rhodes said US intelligence agencies had concluded Bashar al-Assad’s forces had used chemical weapons, including the nerve agent sarin, based on battlefield reports, “descriptions of physiological symptoms” from alleged victims, and laboratory analysis of samples obtained from alleged victims.
However, the full number killed by chemical weapons was “likely incomplete”, Ben Rhodes said in a conference call with reporters.
“Put simply, the Assad regime should know that its actions have led us to increase the scope and scale of assistance that we provide to the opposition,” he said, including direct support to the SMC.
“These efforts will increase going forward.”
Further actions will be taken “on our own timeline”, Ben Rhodes said.
Iraqi authorities say they have uncovered an al-Qaeda plot to use chemical weapons, as well as to smuggle them to Europe and North America.
Iraqi defense ministry spokesman Mohammed al-Askari said five men had been arrested after military intelligence monitored their activities for three months.
Three workshops for manufacturing the chemical agents, including sarin and mustard gas, were uncovered, he added.
Remote-controlled toy planes were also seized at the workshops.
Mohammed al-Askari said they were to have been used to release the chemical agents over the target from a “safe” distance of 1.5 km (0.9 miles).
All of the arrested men had confessed to the plot, and said they had received instruction from another al-Qaeda offshoot, he added.
As the defense ministry spokesman spoke on Iraqi TV, footage was shown of four men with black hoods on their heads, our correspondent adds. Three of them were wearing bright yellow jumpsuits and a fourth was in a brown jumpsuit.
Iraqi authorities have uncovered an al-Qaeda plot to use chemical weapons
Their arrests were possible because of co-operation between Iraqi and foreign intelligence services, Mohammed al-Askari said.
Al-Qaeda in Iraq is believed the only offshoot of the Islamist militant network to have used chemical weapons.
It detonated a 16 crude chlorine bombs in Iraq between October 2006 and June 2007.
Chlorine inhalation made many hundreds of people sick, but no deaths resulting from exposure to the chemical were recorded, US officials said at the time. Instead, the bomb blasts are believed to have caused the fatalities.
At the time, US officials said al-Qaeda appeared to want to use debilitating agents like chlorine in their bombs to cause casualties beyond those hit by the initial explosion.
US and Iraqi troops subsequently killed or detained many of the militants who were building the chlorine-laced bombs and seized much of their stockpiled chemicals.
A letter written by the late al-Qaeda leader Osama Bin Laden five days before he was killed in a US military raid in Pakistan in 2011 urged members of the group’s offshoot in Yemen who he believed were considering using “poison” to be “careful of doing it without enough study of all aspects, including political and media reaction”, according to CNN.
The US has criticized Russia for what it calls an “unfortunate decision” to deliver missiles to the Syrian government.
Chairman of the Joint Chiefs of Staff General Martin Dempsey said the shipment “will embolden the regime and prolong the suffering” that has killed 80,000.
The sophisticated anti-ship missiles could be used to counter any future foreign military intervention, US officials told The New York Times.
Some 1.5 million people have fled the conflict, says the UN refugee agency.
Most have fled to Jordan and Lebanon, but not all have been registered yet, meaning the true total is likely to be far higher, according to the UNHCR.
Meanwhile, Syria’s national production has dropped by 40% and the number of people living below the poverty line has risen from two million to five million in just two years, according to the man in charge of the UN’s plans for reconstructing Syria after the conflict.
Abdullah al-Dardari, a former deputy prime minister in President Bashar al-Assad’s administration, said the rebuilding what has been destroyed would cost up to $80 billion.
The US has criticized Russia for what it calls an “unfortunate decision” to deliver missiles to the Syrian government
Gen. Martin Dempsey’s description of Moscow’s decision to send missiles to Syria as “ill-timed and very unfortunate” comes amid growing alarm that chemical weapons may have been used in the country, something President Barack Obama has said would be “a red line”.
Russia is one of Syria’s few remaining allies and a long-term arms supplier to the Assad regime. Over the years, in contracts worth billions of dollars, it has sold thousands of tanks, artillery units, aircraft, helicopters and defense systems to Damascus.
In 2007, the two countries signed a deal on the supply of Yakhont missiles which, with a range of 300 km (200 miles), could prove a threat to warships in the Mediterranean.
Although there have been growing calls for arms to be channeled to the rebel fighters in Syria, there has so far been very limited enthusiasm in the West for outright military intervention.
But there is concern that the presence of sophisticated Russian-supplied weaponry will make it much harder to agree and carry out such intervention, implement a blockade or conduct targeted airstrikes in the future.
Without confirming reports of the missile shipment, Russia’s foreign minister Sergei Lavrov said the supply of missiles did not break any international rules.
UN Secretary General Ban Ki-moon met Sergei Lavrov in Sochi on Friday to discuss plans for an international conference to try to find a way of ending the Syrian conflict, which would aim to bring together the Syrian opposition and members of Bashar al-Assad’s government.
The UN estimates that 80,000 people have died in the uprising, and that some 4.25 million people have been displaced within the country.
The simmering conflict has raised tensions on Syria’s borders: On Friday, Turkish state media reported at least 10 people were killed when a fuel tank exploded in the southern town of Altinozu in Hatay province, where car bombs killed 50 people last week.
The fuel tank was set alight by smugglers during a raid by police, officials said.
Frustrated by the lack of international consensus on Syria, Turkish PM Recep Tayyip Erdogan has had talks this week with President Barack Obama in Washington where he was expected to call for a more assertive stance.
Recep Tayyip Erdogan said on Friday the UN should discuss imposing a no-fly zone inside Syria at the international conference being mooted.
“With respect to a no-fly zone… it is not a decision that could be taken between the United States and Turkey. It is something that would have to come through the UN Security Council,” he said.
Syria’s Russian-made military:
Nearly 5,000 tanks; 2,500 infantry fighting vehicles; 2,500 self-propelled or towed artillery units
325 Tactical aircraft; 143 helicopters
Nearly 2,000 air defense pieces
295,000 active personnel; 314,000 reserve personnel
According to leading United Nations investigator Carla del Ponte, testimony from victims of the Syrian conflict suggests rebels have used the nerve agent sarin.
Carla del Ponte told Swiss TV there were “strong, concrete suspicions but not yet incontrovertible proof”.
However, she said her panel had not yet seen evidence of government forces using chemical weapons.
Syria has recently come under growing Western pressure over the alleged use of such weapons.
Carla del Ponte, who serves on the UN Independent International Commission of Inquiry on Syria, said in an interview with Swiss-Italian TV: “Our investigators have been in neighboring countries interviewing victims, doctors and field hospitals.
Carla del Ponte said there were strong suspicions that Syrian rebels used sarin
“According to their report of last week, which I have seen, there are strong, concrete suspicions but not yet incontrovertible proof of the use of sarin gas, from the way the victims were treated.”
Carla del Ponte, a former Swiss attorney-general and prosecutor with the International Criminal Tribunal for the former Yugoslavia, did not rule out the possibility that government troops might also have used chemical weapons, but said further investigation was needed.
She gave no details of when or where sarin may have been used.
Her commission was established in August 2011 to examine alleged violations of human rights in the Syrian conflict since March 2011 and is due to issue its latest report to the UN Human Rights Council in Geneva in June.
A separate United Nations team was established to look specifically into the issue of chemical weapons.
The team is ready to go to Syria but wants unconditional access with the right to inquire into all credible allegations.
Both the Syrian government and the rebels have in the past accused each other using chemical weapons.
Sarin, a colorless, odorless gas which can cause respiratory arrest and death, is classed as a weapon of mass destruction and is banned under international law.
Syria may have used chemical weapons against rebels, the White House has said.
US intelligence agencies believe “with varying degrees of confidence” that the nerve agent sarin had been deployed on a “small scale”, and did not say where or when it had been used.
The White House has warned chemical weapons use would be a “red line” for possible intervention, but says this intelligence does not represent proof.
Republicans in Congress called on Thursday for a strong US response.
The assessment was made in letters to lawmakers on Thursday signed by Miguel Rodriguez, White House director of the office of legislative affairs.
“Our intelligence community does assess, with varying degrees of confidence, that the Syrian regime has used chemical weapons on a small scale in Syria, specifically, the chemical agent sarin,” one of the letters said.
But it added: “Given the stakes involved, and what we have learned from our own recent experiences, intelligence assessments alone are not sufficient – only credible and corroborated facts that provide us with some degree of certainty will guide our decision-making.”
The phrase “varying degrees of confidence” is normally used to reflect differences in opinion within the intelligence community.
Syria may have used chemical weapons against rebels, the White House has said
Speaking to reporters in Abu Dhabi on Thursday, US Defence Secretary Chuck Hagel told reporters in Abu Dhabi that the use of sarin “violates every convention of warfare”.
Secretary of State John Kerry said there had been two instances of chemical weapons use in Syria.
The UK Foreign Office echoed the US claims, saying it had “limited but persuasive information from various sources” of chemical weapons use in Syria.
It is understood that Britain obtained samples from inside Syria that have been tested by the Defence Science and Technology Laboratory at Porton Down, Wiltshire.
“Material from inside Syria tested positive for sarin,” a Foreign Office spokesman said.
Syria is believed to possess large quantities of chemical weapons and there has been heightened concern among the international community in recent months about the safety of the stockpiles.
Although there have been numerous accusations, there has so far not been any confirmation that chemical weapons have been used during Syria’s two-year-old conflict.
President Barack Obama warned in December that Syrian President Bashar al-Assad would face “consequences” if he used such weapons.
The letters released on Thursday were sent to powerful US senators John McCain and Carl Levin.
In response, Senator John McCain told reporters: “It’s pretty obvious that red line has been crossed.”
John McCain recommended arming the opposition, a step the White House has been reluctant to take. He also urged taking steps to ensure that Syria’s chemical weapons did not fall into the wrong hands.
“It does not mean boots on the ground,” the Arizona senator added.
Democrat Dianne Feinstein, chair of the Senate Intelligence Committee, called for international action to help secure Syria’s stockpile of chemical arms.
Robert Menendez, the Democratic Chairman of the Senate Foreign Relations Committee, said options included “an internationally recognized no-fly zone, providing lethal assistance to vetted opposition forces, and sanctioning the transfer of arms to the regime”.
White House officials said the US would consult with allies and seek more evidence to confirm their intelligence.
On Tuesday, a senior Israeli military official accused Syrian forces of having used the nerve agent sarin against rebels several times. People can normally recover from small doses.
Speaking at a security conference in Jerusalem, Brigadier General Itai Brun cited photographs of victims foaming at the mouth and with constricted pupils and other unspecified symptoms.
Syria’s government and rebels have accused each other of using chemical weapons. A UN team is trying to enter Syria to investigate.
Sarin is a colorless and highly toxic nerve agent that can cause convulsions, paralysis and death within minutes if it is absorbed through inhalation, ingestion, or contact with skin or eyes.
According to the UN, at least 70,000 people have been killed in the Syrian conflict.
NATO has approved the deployment of Patriot anti-missile batteries along Turkey’s border with Syria.
The long-expected move emerged from a meeting of NATO foreign ministers in Brussels, and amid growing fears that Syria could use chemical weapons.
NATO’s Secretary General Anders Fogh Rasmussen said the ministers had “unanimously expressed grave concerns” about the use of chemical weapons.
Syria has said it would never use such weapons against its own people.
The meeting of the 28-member Western military alliance’s foreign ministers in Brussels follows a request from Turkey to boost its defences along the border.
NATO has approved the deployment of Patriot anti-missile batteries along Turkey’s border with Syria
In a statement, NATO said it had “agreed to augment Turkey’s air defence capabilities in order to defend the population and territory of Turkey and to contribute to the de-escalation of the crisis along the alliance’s border”.
Recent intelligence assessments have indicated Damascus is contemplating using ballistic missiles, potentially armed with chemical warheads.
Speaking after the meeting, Anders Fogh Rasmussen told reporters that the foreign ministers had “unanimously expressed grave concerns” about the reports, saying: “Any such action would be completely unacceptable and a clear breach of international law.”
He would not give further details on the deployment, but said it would ensure effective protection of Turkey against any missile attack, whether carrying chemical weapons or not.
NATO officials have previously made clear such a move would be purely defensive.
Anders Fogh Rasmussen, NATO Secretary General, has underlined President Barack Obama’s warning to the Syrian government not to use chemical weapons against its own people.
At a NATO foreign ministers’ meeting in Brussels, Anders Fogh Rasmussen said their use would be “completely unacceptable”.
The foreign ministers are expected to approve the deployment of Patriot anti-missile batteries to Turkey.
The move is designed to defend Turkey’s border with Syria.
Activists say more than 40,000 people have been killed since the Syrian uprising against President Assad began in March 2011. Hundreds of thousands of people have fled the country and another 2.5 million are displaced within its borders.
On Tuesday, a teacher and at least 28 students were killed in a rocket attack on their school inside the Wafideen refugee camp, 20 km (15 miles) north-east of Damascus.
The origin of the firing was not clear – state media said it had been a rebel mortar attack.
Speaking ahead of the NATO meeting, Anders Fogh Rasmussen told reporters: “The possible use of chemical weapons would be completely unacceptable for the whole international community.
“If anybody resorts to these terrible weapons, then I would expect an immediate reaction from the international community.”
Anders Fogh Rasmussen, NATO Secretary General, has underlined President Barack Obama’s warning to the Syrian government not to use chemical weapons against its own people
The meeting of the 28-member Western military alliance’s foreign ministers in Brussels follows a request from Turkey to boost its defences along the border. NATO officials have made clear such a move would be purely defensive.
Barack Obama has warned Syrian President Bashar al-Assad he would face “consequences” if he used chemical weapons against his people.
“The world is watching. The use of chemical weapons is and would be totally unacceptable,” said Barack Obama in a speech at the National Defense University in Washington.
“If you make the tragic mistake of using these weapons there will be consequences and you will be held accountable.”
A Syrian official has insisted the country would “never, under any circumstances” use such weapons, “if such weapons exist”.
A NATO team has already visited a number of sites in Turkey in preparation for the deployment of Patriot batteries, which could be used to shoot down any Syrian missiles or warplanes that stray over the border.
The missile deployment is likely to be approved despite opposition from Russia, whose foreign minister is also attending Tuesday’s meeting in Brussels.
But analysts say any deployment – possibly supplied by the US, Germany or the Netherlands – could take weeks.
Syrian opposition fighters have reportedly made dramatic gains recently, and several government mortar shells – aimed at rebel targets close to the border – have landed across its 900-km (560-mile) border with Turkey.
Ankara’s request for NATO to deploy the anti-missile batteries came after intelligence assessments that Damascus was contemplating using ballistic missiles, potentially armed with chemical warheads, reports say.
Syria is believed to hold chemical weapons – including mustard gas and sarin, a highly toxic nerve agent – at dozens of sites around the country.
The CIA has said those weapons “can be delivered by aircraft, ballistic missile and artillery rockets”.
One unnamed US official told the New York Times on Monday that the level of concern in Washington was such that contingency plans were being prepared.
On Monday the United Nations said it was pulling “all non-essential international staff” out of Syria, with as many as 25 out of 100 international staff expected to leave this week.
The European Union has withdrawn its mission altogether. The ambassador and head of delegation to Syria, Vassilis Bontosoglou, left Damascus with his six remaining international staff members on Tuesday morning.
Although the head of the Arab League Nabil al-Arabi told AFP on Monday that the Syrian government could fall “any time”, it still holds the capital, parts of the second city Aleppo, and other centres.
Syrian foreign ministry spokesman Jihad Makdissi is said to have fled the country, amid reports he has been dismissed, ostensibly for making statements out of line with government policy.
Barack Obama has warned Syrian President Bashar al-Assad he will face “consequences” if he uses chemical weapons against his people.
“The world is watching. The use of chemical weapons is and would be totally unacceptable,” said President Barack Obama.
A Syrian official has insisted it would “never, under any circumstances” use such weapons, “if such weapons exist”.
Meanwhile, the United Nations says it is pulling “all non-essential international staff” out of Syria.
As many as 25 out of 100 international staff could leave this week, the UN news agency Irin reported, while all humanitarian missions outside Damascus will be halted for the time being.
In a speech on nuclear non-proliferation at the National Defense University in Fort McNair, Barack Obama said: “We’ve worked to keep weapons from spreading, whether it was nuclear material in Libya or nor chemical weapons in Syria.
“We simply cannot allow the 21st century to be darkened by the worse weapons of the 20th century.”
“And today I want to make it absolute clear to Assad and anyone who is under his command… If you make the tragic mistake of using these weapons there will be consequences and you will be held accountable.”
But Damascus rejected allegations it was preparing to use such weapons.
A foreign ministry spokesman was quoted by state television as saying: “Syria confirms repeatedly it will never, under any circumstances, use chemical weapons against its own people, if such weapons exist.”
Barack Obama has warned Syrian President Bashar al-Assad he will face consequences if he uses chemical weapons against his people
Syria is believed to hold chemical weapons – including mustard gas and sarin, a highly toxic nerve agent – at dozens of sites around the country.
The CIA has said those weapons “can be delivered by aircraft, ballistic missile, and artillery rockets”.
One unnamed US official spoke to the New York Times of “potential chemical weapon preparation”.
The White House says the level of concern was such that Washington is preparing contingency plans. The crisis in Syria had increased the risk of humanitarian workers in the country due to the increased risk of indiscriminate shooting by fighting forces., said Sabir Mughal, the UN’s chief security adviser in Syria.
The European Union, which has a diplomatic office in the Syrian capital, has confirmed it too is “to reduce activities in Damascus to a minimum level due to the current security conditions”.
Earlier, Egypt Air ordered the return of a flight on its way to Damascus amid reports of a “bad security situation” around the airport – only a day after ending its suspension of flights following violence around the airport and in the capital’s suburbs last week.
Syrian Foreign Ministry spokesman Jihad Makdissi is reported to have already left the country, even before reports that he had been dismissed, ostensibly for making statements out of line with government policy.
Rebels have been making gains on the ground, and the head of the Arab League has said the Syrian government could fall at any moment.
But it still holds the capital, parts of the second city Aleppo, and other centres and one diplomat said it still has a lot of fight left in it.
Intelligence that the Syrian government was contemplating the use of the missiles is what led neighboring Turkey to request NATO Patriot missile defences along its borders, Turkish officials were quoted as saying on Sunday.
Several Syrian mortar shells – aimed at rebel targets close to the border – have landed in Turkish territory in recent weeks, leading Ankara to ask NATO for the deployment of the sophisticated anti-missile batteries.
But Russian President Vladimir Putin, after talks with Turkish Prime Minister Recep Tayyip Erdogan in Istanbul on Monday, warned against such a move, fearing it would “exacerbate” rather than “defuse” tensions on the border.
Moscow has remained a key ally of Syria during the 22-month conflict, while Ankara now backs the rebels trying to oust President Bashar al-Assad.
There was no breakthrough on how to “regulate the situation” in Syria, said Vladimir Putin, while emphasizing that the Turkish and Russian “assessment of the situation completely coincides”.
“We are not advocates of the incumbent Syrian leadership,” he said.
The UK has decided to join the US in warning Syria that the use or threat of chemical weapons would force them “to revisit their approach”.
The warning came after a telephone call between Prime Minister David Cameron and US President Barack Obama.
David Cameron also spoke to French President Francois Hollande. The three discussed building support for the opposition.
Earlier, Chinese state media accused Barack Obama of using the chemical arms issue as an excuse for military intervention.
Also on Wednesday, fierce fighting raged in the northern Syrian city of Aleppo and in Damascus, which residents said had witnessed the heaviest attack by government forces since the army re-asserted its control of the capital last month.
A Downing Street spokesman said the “appalling situation that continues in Syria” was the main focus of David Cameron’s conversations with Francois Hollande and Barack Obama.
The UK has decided to join the US in warning Syria that the use or threat of chemical weapons would force them "to revisit their approach"
David Cameron and Barack Obama both agreed “that the use – or threat – of chemical weapons was completely unacceptable and would force them to revisit their approach so far”, said the spokesman.
The comments echoed those by Barack Obama earlier in the week, when he said he would change his thinking on intervention if Syria used chemical weapons.
The two leaders, along with Francois Hollande, discussed “how to build on the support already given to the opposition” and “help a potential transitional Syrian government after the inevitable fall of [President Bashar al-] Assad”.
Barack Obama and David Cameron called for a “credible opposition” that would “show real unity of purpose and coherence in working towards transition”.
The three leaders also discussed the plight of Syrian refugees.
The spokesman said: “The prime minister emphasized the need to work with the UN and… that more should be done by the international community to channel humanitarian aid through the UN appeal.”
Earlier, the Chinese state news agency Xinhua accused Western powers of “digging deep for excuses to intervene militarily”.
In its commentary, Xinhua criticized Barack Obama’s earlier remarks as “dangerously irresponsible” and said they would aggravate the conflict, reducing the chances of a political settlement.
China insists a ceasefire and UN-led mediation remain the best ways to end Syria’s woes.
China and Russia have both blocked attempts to impose UN sanctions on Syria.
A Russian foreign ministry source told the Kommersant newspaper on Wednesday that Moscow believed Syria had no intention of using its chemical weapons and was able to safeguard them.
Fierce fighting continued across Syria on Wednesday.
An aerial bombardment preceded an assault by tanks on several areas of Damascus.
Activists said at least 37 people had been killed in the capital, in the areas of Kafar Soussa and Nahr Eishah.
A journalist working for the state-run Tishreen newspaper, Mosaab al-Odallah, was killed by the military during house-to-house searches in Nahr Eishah, activists and friends said.
Mosaab al-Odallah was said to be sympathetic to the opposition.
Reuters reporters said they had heard shells and gunfire every minute in the northern city of Aleppo.
Elsewhere, rebels and troops fought for control of a military base and airfield near the eastern town of Albu Kamal.
Activists said at least three people were killed in a helicopter bombardment of Qastoun, in Hama province.
Shelling was also reported in Deraa, and heavy fighting was reported in Deir Ezzor in the east.
The opposition Syrian Observatory for Human Rights said at least 115 people, including 71 civilians, were killed across the country on Wednesday.
The figures cannot be independently verified.
Opposition activists say more than 20,000 people – mostly civilians – have died since the uprising against Bashar al-Assad began last year.
Russia has warned against unilateral action in Syria after President Barack Obama said the US might intervene militarily if Damascus used chemical weapons on the rebels.
Russian Foreign Minister Sergei Lavrov said there should be no outside interference and countries should “strictly adhere to the norms of international law”.
On Monday, President Barack Obama said the deployment of chemical weapons represented a “red line” for the US.
Meanwhile, troops are reported to have stormed a western suburb of Damascus.
On Tuesday, Russia’s foreign minister held talks in Moscow with China’s top diplomat, State Councilor Dai Bingguo, and a Syrian government delegation to discuss the conflict, which the UN says has left 18,000 people dead.
Russian Foreign Minister Sergei Lavrov said there should be no outside interference and countries should "strictly adhere to the norms of international law"
After meeting Dai Bingguo, Sergei Lavrov said Moscow and Beijing based their diplomatic co-operation on “the need to strictly adhere to the norms of international law and the principles contained in the UN Charter, and not to allow their violation”.
“I think this is the only correct path in today’s conditions,” Sergei Lavrov added.
He said only the UN Security Council could authorize the use of force against Syria, and warned against imposing “democracy by bombs”.
He also told Syrian Deputy Prime Minister Qadri Jamil that he wanted to hear his plans for “further actions to shift the situation into the channel of political dialogue in order for Syrians themselves to decide their fate without external interference”.
Qadri Jamil said external interference was “hindering efforts for Syrians themselves to resolve this problem”.
Russia and China have opposed intervention in Syria since anti-government protests erupted in March 2011. They have vetoed three Security Council resolutions seeking to press President Bashar al-Assad to end the violence.
On Monday, Barack Obama warned Syria’s government at a news conference that “there would be enormous consequences if we start seeing movement on the chemical weapons front or the use of chemical weapons”.
Barack Obama said that he had not ordered military engagement “at this point”, but added that the US was monitoring the situation carefully and had made contingency plans.
In July, the Syrian government admitted that it had chemical and biological weapons and might use them in case of any “external aggression”. But it insisted they would “never be used in the Syrian crisis, no matter what the internal developments”.
Correspondents say there is also growing unease in Washington that Syria’s chemical weapons may fall into what Barack Obama termed “the hands of the wrong people”.
On Tuesday, soldiers were said to have stormed the western Damascus suburb of Muadhamiya.
At least 23 people were killed and shops and houses were set on fire after government forces entered Muadhamiya at dawn, looking for rebel fighters, opposition activists said.
The bodies of several men who had been shot at close range were found inside buildings after the troops withdrew from the town, they added.
There was reportedly also heavy shelling and fierce fighting in the southern town of Herak and in the northern city of Aleppo, where the Japanese journalist, Mika Yamamoto, was killed on Monday.
A commander in the Free Syrian Army, Col Abdul Jabbar al-Ukaidi, told the AFP news agency that its fighters now controlled “more than 60%” of Aleppo, although a security source in Damascus dismissed the claims.
President Barack Obama has said the use of chemical weapons by Syria would be a “red line” that would change his thinking on intervention in the crisis.
Barack Obama said he had “at this point not ordered military engagement”.
But he added: “There would be enormous consequences if we start seeing movement on the chemical weapons front or the use of chemical weapons.”
Earlier the new UN special envoy to Syria faced criticism for refusing to say whether President Bashar al-Assad must quit.
Barack Obama, speaking to reporters at a White House briefing, said the deployment or use of biological weapons would widen the conflict in the region.
He said: “It doesn’t just include Syria. It would concern allies in the region, including Israel, and it would concern us.”
He warned President Bashar al-Assad and “other players on the ground” about the use or movement of such weapons.
He said: “A red line for us is [if] we see a whole bunch of chemical weapons moving around, or being utilized. That would change my calculus.”
President Barack Obama has said the use of chemical weapons by Syria would be a "red line" that would change his thinking on intervention in the crisis
Syria holds the world’s fourth-largest stockpile of chemical weapons. Last month a Syrian foreign ministry spokesman said the weapons would never be deployed inside Syria.
However, the US has seen unconfirmed reports recently that the Syrian authorities have been moving the country’s chemical arms stockpile.
Fighting continued in several Syrian cities on Monday, including Damascus, Deraa and Aleppo.
A Japanese journalist, Mika Yamamoto, was killed by gunfire in Aleppo, the country’s foreign ministry has confirmed.
Mika Yamamoto, 45, was a veteran war reporter, working for Japan Press.
The UN says more than 18,000 people have been killed in the conflict, 170,000 have fled Syria and 2.5 million need aid within the country.
Earlier on Monday, the UN’s new envoy to Syria, Lakhdar Brahimi said he was “not in a position to say yet” whether President Assad should go, but was “committed to finding a solution”.
Lakhdar Brahimi, a former Algerian foreign minister, last week succeeded Kofi Annan who resigned after both sides largely ignored his peace plan.
On Sunday, UN observers ended their mission to verify its implementation.
Their departure came after the UN Security Council agreed to allow their mandate to expire at midnight, and instead set up a new civilian office in Damascus to pursue political contacts that might lead to peace.
Since being confirmed as the new UN and Arab League envoy to Syria, Lakhdar Brahimi has acknowledged that he has no concrete ideas of how to end the conflict, which he believes has been a civil war for some time.
On Monday, he said he was not ready to say whether President Assad should step down despite widespread international condemnation of his government’s crackdown on dissent since protests erupted in March 2011.
“I am not in a position to say yet, because I was appointed a couple of days ago. I am going to New York for the first time to see the people who I am going to work for, and I am going to Cairo see the Arab League,” he explained.
After announcing his resignation, Lakhdar Brahimi’s predecessor, Kofi Annan, said: “It is clear that President Bashar al-Assad must leave office.”
The main opposition coalition, the Syrian National Council (SNC), said Lakhdar Brahimi’s stance showed “disregard for the blood of the Syrian people and their right of self-determination” and demanded he apologize.
Lakhdar Brahimi stressed that he was “committed to finding a solution full stop”.
“I am a mediator. I haven’t joined any Syrian party. I am a mediator and a mediator has to speak to anybody and everybody without influence or interest,” he added.
“Then I’ll make up my mind about what to say and what to do.”