According to reports from Seoul, South Korea has a plan to annihilate Pyongyang if North Korea shows any signs of mounting a nuclear attack.
A military source told the Yonhap news agency every part of Pyongyang “will be completely destroyed by ballistic missiles and high-explosives shells”.
Yonhap has close ties to South Korea’s government and is publicly funded.
On September 9, North Korea carried out what it said was its fifth, and largest, nuclear test.
The international community is considering its response.
The US says it is considering its own sanctions, in addition to any imposed by the UN Security Council, Japan and South Korea.
Pyongyang responded on September 11 by calling the threats of “meaningless sanctions… highly laughable”.
The South Korean military official told Yonhap that Pyongyang districts thought to be hiding the North’s leadership would be particularly targeted in any attack. Pyongyang, the source said, “will be reduced to ashes and removed from the map”.
News of South Korea’s attack plan for North Korea is believed to have been revealed to parliament following September 9 nuclear test.
Meanwhile, the US’s special envoy for North Korea says Washington is considering taking unilateral action against Pyongyang.
Sung Kim said: “North Korea continues to present a growing threat to the region, to our allies, to ourselves, and we will do everything possible to defend against that growing threat.
“In addition to sanctions in the Security Council, both the US and Japan, together with [South Korea], will be looking at any unilateral measures as well as bilateral measures as well as possible trilateral cooperation.”
North Korea is banned by the UN from any tests of nuclear or missile technology and has been hit by five sets of UN sanctions since its first test in 2006.
The secretive country said September 9 test had been of a “nuclear warhead that has been standardized to be able to be mounted on strategic ballistic rockets”.
Estimates of the explosive yield of the latest blast have varied. South Korea’s military said it was about 10 kilotonnes, enough to make it the North’s “strongest nuclear test ever”. Other experts say initial indications suggest 20 kilotonnes or more.
The nuclear bomb dropped by the US on Hiroshima in 1945 had a yield of about 15 kilotonnes.
North Korea has successfully carried out its fifth nuclear test, Pyongyang has confirmed.
The government announcement on state media came hours after a seismic event was detected near North Korea’s nuclear test site.
According to South Korean officials, it is North Korea’s biggest ever test, raising fears the state has made real nuclear advances.
South Korea’s President Park Geun-hye called it an act of “self-destruction” showing the “maniacal recklessness” of leader Kim Jong-un. The US warned of “serious consequences”.
China’s foreign ministry said Beijing was resolutely opposed to the test and urged North Korea to avoid further action that would worsen the situation.
North Korea said the test had been of a “newly developed nuclear warhead” and that it was now capable of mounting a nuclear device on ballistic rockets.
South Korea’s military has suggested that the explosive yield of this blast could be almost twice that of the previous nuclear test. Analysts have expressed fears this could mean North Korea is a step closer to having a useable nuclear weapon.
Park Geun-hye, who is cutting short an overseas visit, said the test was a “grave challenge” to the international community that would “only earn more sanctions and isolation” for North Korea.
“Such provocation will further accelerate its path to self-destruction,” she said.
Japan’s PM Shinzo Abe said his country “absolutely cannot condone” any such test and would “protest adamantly” to Pyongyang.
“North Korea’s nuclear development is becoming a graver threat to Japan’s safety and severely undermines the peace and safety of the region and the international community,” he said.
The White House said President Barack Obama had spoken to both Park Geun-hye and Shinzo Abe after the latest test.
A statement from press secretary Josh Earnest said Barack Obama had “reiterated the unbreakable US commitment to the security of our allies in Asia and around the world”.
“The president indicated he would continue to consult our allies and partners in the days ahead to ensure provocative actions from North Korea are met with serious consequences.”
China’s foreign ministry statement read: “Today, [North Korea] again conducted a nuclear test despite widespread international opposition – the Chinese government firmly opposes the test.”
The test was first detected as a 5.3 magnitude earthquake on September 9 in north-east North Korea, close to its Punggye-ri underground nuclear test site.
As with previous nuclear tests, the waveform generated indicated it had not been naturally occurring.
South Korea’s Joint Chiefs of Staff later said the detonation had a yield of about 10 kilotonnes, making it North Korea’s “strongest nuclear test ever”.
That is almost twice the power of its last test in January, which Pyongyang said at the time had been a hydrogen bomb. Many analysts cast doubt on that claim. The bomb dropped by the US on Hiroshima in 1945 had a yield of about 15 kilotonnes.
A fifth test has long been expected. In recent weeks, satellite imagery has shown increased activity at Punggye-ri.
North Korea also often uses nationally important dates as an opportunity for a show of military strength. September 9 is its National Day, celebrating the founding of the current regime.
It is likely to be some time before the scale and manner of the test are independently confirmed.
Japan has dispatched military aircraft to collect air samples to monitor for radiation, while China said it was monitoring radiation levels close to its borders with North Korea.
North Korea is banned by UN sanctions from any tests of nuclear or missile technology.
In recent months it has conducted a series of ballistic missile launches – some of which reached Japanese waters – and has unleashed a rising tide of aggressive rhetoric, threatening nuclear attacks on its enemies.
North Korea has also been angered by a US and South Korean plan to install an anti-missile defense system in the South and by the allies’ massive annual joint military exercises, which are still taking place.
International sanctions on North Korea were considerably toughened in response to previous nuclear and missile tests but had little impact on Pyongyang’s nuclear arms program.
North Korea has responded to a UN move towards a probe into the country’s human rights violations by threatening to conduct a nuclear test.
The North Korean foreign ministry on November 20 accused the US of orchestrating a recent UN resolution calling for the investigation.
North Korea previously conducted nuclear tests in 2006, 2009 and 2013.
Its threat comes as new satellite images emerge indicating fresh activity at a North Korean nuclear facility.
A UN human rights committee on November 18 passed a resolution calling on the Security Council to refer North Korea to the International Criminal Court for alleged crimes against humanity.
Pyongyang said the resolution was based on “fabricated testimonies” from North Korean defectors and “slander against Pyongyang”.
The resolution’s approval was a “grave political provocation” by the US and such “aggression..is leaving us unable to further refrain from staging a new nuclear test”.
It added that its military deterrence “will be beefed up limitlessly” to guard against the US.
A US State Department spokesman said: “It would certainly be unfortunate to threaten with that kind of activity in response to the legitimate focus on North Korea’s human rights situation by the international community.”
North Korea has previously rejected claims of human rights violations.
Following a UN report alleging the country was committing “unspeakable atrocities”, a Pyongyang official held a rare open briefing last month where he denied the existence of prison camps, and said there were only detention centers.
Tuesday’s resolution drew heavily on the report, which was released in February.
Analysts however say that it is unlikely that the Security Council will allow North Korea to be tried in the ICC, as Russia and China – which voted against the resolution – sit on the Council.
North Korea’s nuclear test threat comes as a US research institute published new evidence that Pyongyang may be restarting a plant that can reprocess nuclear fuel into weapons-grade plutonium.
The US-Korea Institute posted recent satellite images showing activity at a radiochemical laboratory at the Yongbyon facility on 38 North, its website devoted to North Korea analysis.
The pictures show a cooling tower emitting steam, vehicles coming and going, and piles of “grey material” stacked outside a facility believed to be manufacturing fuel.
North Korea has proposed high-level talks with the United States, days after cancelling a meeting with South Korean officials.
The National Defense Commission said in a statement it wanted “serious discussions” with the US to “secure peace and stability in the region”.
US and North Korean officials meet periodically, but have not engaged in high-level talks since 2009.
Earlier this year Pyongyang threatened to launch a nuclear attack on both the US and South Korea.
For years the North has cajoled the US and regional neighbors with a mixture of dire threats and promises of co-operation.
Correspondents say Pyongyang is constantly trying to improve its bargaining position to extract more food aid or fuel.
However, the regime has conducted three nuclear-weapons tests in recent years that have even angered its only ally, China.
Beijing co-authored a Security Council resolution imposing new sanctions on the regime earlier this year in response to its latest nuclear test.
North Korea has proposed high-level talks with the United States
The North responded with increasingly hysterical threats, cut hotlines used for emergency communication with the South and withdrew workers from a joint industrial park near the border.
Pyongyang finally agreeing to open talks with the South earlier this week.
But on Thursday, the North cancelled the meeting, accusing the South of “deliberate disturbance” by changing the head of its delegation.
On Friday, Pyongyang issued an appeal calling on the South to change fundamentally its “policy of confrontation”.
The National Defense Commission on Sunday said that in the meantime it proposed “high-level talks between the North and the US to secure peace and stability in the region and ease tension on the Korean peninsula”.
The commission said it was willing to have “serious discussions on a wide range of issues, including the US goal to achieve the world free of nuclear arsenal”.
Washington could decide the time and venue, but there should be no preconditions, the statement said.
The National Defense Commission is headed by North Korea’s leader, Kim Jong-un, who succeeded his father in December 2011.
For years, delegates from North Korea engaged with the US, Russia, South Korea, Japan and China in talks over its nuclear programme.
The regime was rewarded with food and fuel aid when it gave concessions, such as destroying a cooling tower at the Yongbyon nuclear plant in 2008.
However, North Korea walked out of the talks in April 2009 after the UN criticized a rocket launch.
North Korea is reactivating facilities at its moth-balled Yongbyon nuclear reactor, a US think-tank says.
Start-up could be one to two months away, it said, but there was uncertainty over the availability of fuel rods to power the reactor.
Pyongyang vowed to restart the reactor, which makes weapons-grade plutonium, in April amid severe regional tensions.
The Yongbyon reactor was shut down in July 2007 as part of a disarmament-for-aid deal.
The cooling tower at the facility was later destroyed, but then the disarmament deal stalled.
North Korea’s decision to restart followed its third nuclear test on February 12, which led to expanded UN sanctions.
The information came from the 38 North website, which is part of the US-Korea Institute at Johns Hopkins University in the US.
Its report said that recent satellite imagery showed that North Korea had “essentially finished repairing the cooling system necessary to restart and operate the reactor”.
North Korea is reactivating facilities at its moth-balled Yongbyon nuclear reactor
The cooling tower that was destroyed had not been repaired, but instead a secondary cooling system had been employed. Work was also ongoing at a spent fuel facility, it said.
Piles of construction materials were visible at the site and what could be a new drainage ditch for water from the reactor building was being dug, it said.
The reactor “may be one to two months from start-up. However, the availability of fresh fuel rods to power the reactor – a key factor that will determine when the North will restart the facility – remains unclear,” it said.
Once operational, the reactor could produce “approximately six kilograms of plutonium per year that can be used for manufacturing nuclear weapons”, it added.
North Korea has conducted three nuclear tests since 2006. Analysts believe the first two tests used plutonium as the fissile material, but it is not known whether the third used plutonium or uranium.
While North Korea has depleted its stocks of “reactor-grade” plutonium needed to make the weapons-grade variety, it has plentiful reserves of uranium ore. It also has a uranium enrichment facility at Yongbyon which a US scientist said could be converted to produce highly enriched uranium bomb fuel.
After UN sanctions were expanded following the most recent nuclear test, in February, North Korea issued multiple threats against US and regional interests, vowed to reactivate Yongbyon and cut both official communications and key business ties with South Korea.
Operations at the jointly-run inter-Korean Kaesong industrial zone remain suspended – the first such stoppage since the project began.
But the threats have diminished in recent weeks and last month, North Korea sent a top envoy to Beijing – its first such move since its nuclear test.
Later this week, the US and Chinese presidents meet in California for their first summit, with North Korea likely to be high on the agenda.
South Korea has decided to raise its alert level to “vital threat” following reports that North Korea is preparing for a missile test.
At least one ballistic missile with an estimated 2,000-mile (3,000 km) range is fuelled and ready for launch, US and South Korean sources say.
Pyongyang has been making bellicose threats against South Korea, Japan and US bases in the region.
The threats follow tough new UN sanctions imposed on North Korea last month following its third nuclear test in February this year.
Separately, an initial investigation by South Korea into a major cyber attack last month that affected a number of banks and broadcasters has said North Korea is to blame.
affected a number of banks and broadcasters has said the North is to blame.
North Korea is believed to have completed preparations for a missile launch after it moved two Musudan missiles to its east coast, Yonhap news agency says.
In anticipation, the South Korea-US Combined Forces have raised their alert level to Watchcon 2 (Vital threat), to increase surveillance monitoring, Yonhap quoted a senior military official as saying.
North Korea unveiled the Musudan missile during a military parade in 2010 but has yet to test it. There are reports, however, that it may have been sold to Iran and tested there.
The launch could happen “anytime from now”, South Korean Foreign Minister Yun Byung-se told parliament.
A test launch would be a violation of UN Security Council Resolution 1718, passed in 2006, which states the North “must not conduct any further nuclear test or launch of a ballistic missile”.
North Korea has tested intermediate range missiles before and during periods of crisis and tension.
While another test launch would certainly be seen as provocative, it is unlikely to have any major, short-term military significance unless it goes wrong.
The raising of South Korea’s alert status comes as Japan deployed anti-missile defenses in Tokyo as a precaution.
“We are on high alert,” said Japan’s Defence Minister Itsunori Onodera.
A number of travel agencies in China have reported that tourist trips into North Korea have been suspended.
One travel agent in the north-eastern city of Dandong told Reuters news agency: “All [tourist] travel to North Korea has been stopped from today and I’ve no idea when it will restart.”
The border remains open to commercial traffic.
Meanwhile, an official investigation by South Korea into last month’s cyber attack traced the malicious codes used to six computers in North Korea.
“We’ve collected a lot of evidence to determine the North’s Reconnaissance General Bureau led the attack, which had been prepared for at least eight months,” a spokesman for the Korea Internet and Security Agency said.
The attack on March 20 severely affected the KBS, MBC and YTN broadcasters and operations at the Shinhan, NongHyup and Jeju banks.
Yesterday North Korea has warned foreigners in South Korea to take precautions in case of war and UN Secretary-General Ban Ki-moon warned the crisis on the Korean peninsula may become “uncontrollable”.
Ban Ki-moon once again urged North Korea to tone down its “provocative rhetoric” and to keep open a joint North-South Korean industrial complex.
North Koreans failed to report for work at the Kaesong complex on Tuesday, suspending one of the few points of co-operation with South Korea.
North Korea has announced today it is withdrawing all its workers from the joint-Korean Kaesong industrial zone and suspending operations there.
The move follows weeks of warlike rhetoric from Pyongyang after it was sanctioned by the UN for carrying out its third nuclear test in February.
Kaesong industrial park was established almost a decade ago and had been a symbol of co-operation between North and South Korea.
However, a North Korean official said it could now be closed permanently.
In a statement, South Korea’s Unification Ministry said the decision “cannot be justified in any way and North Korea will be held responsible for all the consequences,” the AFP news agency reports.
Kaesong complex, just over the border in North Korea, employs more than 50,000 North Korean workers but is funded and managed by South Korean firms.
North Korea has announced today it is withdrawing all its workers from the joint-Korean Kaesong industrial zone and suspending operations there
Pyongyang has already banned South Koreans from entering, but during a visit to the site, Kim Yang-gon, secretary of the party’s Central Committee, said North Korea would now “temporarily suspend the operations in the zone and examine the issue of whether it will allow its existence or close it”.
The North’s KCNA news agency quoted Kim Yang-gon as saying that South Korea and the US “insult the country’s dignity and make the zone a starting point of war”.
“How the situation will develop in the days ahead will entirely depend on the attitude of the South Korean authorities,” Kim Yang-gon said.
The statement made no reference to the nearly 500 South Koreans who are in Kaesong as managers.
One South Korean told the Associated Press he had heard nothing about the order from the North Korean government.
“North Korean workers left work at six o’clock today as they usually do. We’ll know tomorrow whether they will come to work,” he said.
Earlier, South Korean officials played down reports that the North could be about to carry out a nuclear test.
A defense ministry spokesman said the widely reported activity detected at the Punggye-ri underground test site appeared to be routine and that there was “no indication that a nuclear test is imminent”.
UN Secretary General Ban Ki-moon said such a nuclear test would be a “provocative measure”, and warned that North Korea cannot continue “confronting and challenging the authority of the Security Council and directly challenging the whole international community”.
Russia and China have called for calm and a return to dialogue.
Speaking during a visit to Germany, Russian President Vladimir Putin said that as a neighbor of North Korea his country was “worried about the escalation” of tensions.
Vladimir Putin warned there was a risk of a conflict on the Korean peninsula which would make the Chernobyl nuclear disaster “seem like a child’s fairy tale”.
The UN imposed tough sanctions on North Korea following its third nuclear test on February 12.
Pyongyang has responded by issuing almost daily threats to use nuclear weapons and saying it would restart its nuclear reactor.
North Korea has also shut down an emergency military hotline between Seoul and Pyongyang.
Last week it warned it would not be able to guarantee the safety of foreign embassy staff after April 10, and that countries should begin evacuating their diplomatic staff.
North Korea’s state media have been broadcasting a continuing diet of war and retribution with programmes about biochemical war, nuclear war and military preparations dominating the listing.
However, some analysts have suggested that the rhetoric is in large part designed to shore up the standing of a young, inexperienced leader, Kim Jong-un.
Meanwhile, Japan’s defence ministry said the country’s armed forces have been ordered to shoot down any North Korean missile headed towards its territory.
Over the weekend, the US cancelled a scheduled test of its Minuteman III ballistic missile, citing concerns that it could be misinterpreted by Pyongyang.
North Korea appears to be preparing for a fourth nuclear test, according to South Korean officials.
South Korean Unification Minister Ryoo Kihl-jae told lawmakers there were signs of increased activity in North Korea’s main nuclear test site.
North Korea has stepped up its habitual fiery rhetoric against the US and South Korea in recent weeks.
Correspondents say it is unclear whether a test is being prepared or it is a ruse to boost the sense of crisis.
Ryoo Kihl-jae did not elaborate on the specific intelligence which led South Korea to suspect the North was set to carry out its fourth nuclear test.
North Korea appears to be preparing for a fourth nuclear test, according to South Korean officials
But when asked about a news report that North Korea had stepped up activity at the underground site it has used in previous tests, he said “there are such signs”.
Kim Min-seok, a spokesman for South Korea’s defense ministry, said it was possible that the North could fire a ballistic missile and conduct a nuclear test at the same time.
But South Korean official Yonhap news agency quoted him as playing down the threat of an imminent test, saying there were several facilities at the nuclear test site so the movement of vehicles and people there was expected.
“Currently, there is no new movement to add on to the previous briefing,” he said.
Newspaper JoongAng Ilbo quoted an unnamed South Korean official as saying that South Korean intelligence had detected “increased activity of labor forces and vehicles” at the Punggye-ri nuclear test site in the country’s north-east.
“We are closely monitoring the ongoing situation, which is very similar to the situation ahead of the third nuclear test,” the official told the newspaper.
“We are trying to figure out whether it is a genuine preparation for a nuclear test or just a ploy to heap more pressure on us and the US.”
The UN imposed tough sanctions on North Korea last month following its third nuclear test. Pyongyang responded by stepping up angry rhetoric, including threats to use nuclear weapons and restarting its nuclear reactor.
In recent weeks, North Korea has shut down an emergency military hotline between Seoul and Pyongyang, stopped South Koreans from working at the Kaesong joint industrial complex and warned it would not be able to guarantee the safety of foreign embassy staff in the event of a war.
On Monday, the North Korea’s state news agency said a senior official had visited the Kaesong complex and told workers there to prepare for all possible developments.
Analysts have suggested that the rhetoric is in large part designed to shore up the standing of a young, inexperienced leader, Kim Jong-un, in the eyes of his own people.
North Korea’s state media have been broadcasting a continuing diet of war and retribution with programmes about biochemical war, nuclear war and military preparations dominating the listing.
Meanwhile, Japan’s defense ministry said the country’s armed forces have been ordered to shoot down any North Korean missile headed towards its territory.
Over the weekend, the US cancelled a scheduled test of its Minuteman III ballistic missile, citing concerns that it could be misinterpreted by Pyongyang.
China has appealed for calm on the Korean peninsula, hours after North Korea said it had ended all non-aggression pacts with South Korea and threatened pre-emptive nuclear strikes.
China, North Korea’s only major ally, said all sides should continue to talk and avoid “further escalation”.
Pyongyang has reacted angrily to another round of sanctions imposed by the UN over its recent nuclear test.
The sanctions restrict luxury goods imports and banking activities.
Beijing provides fuel, food and diplomatic cover to Pyongyang.
It has repeatedly voted in favor of UN sanctions imposed over the nuclear programme, but enforcement of the measures in China is patchy.
Hua Chunying of China’s foreign ministry told a news conference on Friday: “China and North Korea have normal country relations. At the same time, we also oppose North Korea’s conducting of nuclear tests.
“China calls on the relevant parties to be calm and exercise restraint and avoid taking any further action that would cause any further escalations.”
China has appealed for calm on the Korean peninsula, hours after North Korea said it had ended all non-aggression pacts with South Korea and threatened pre-emptive nuclear strikes
Chinese and US officials drafted the UN resolution passed on Thursday.
It contains similar measures to earlier resolutions, but the US said it had significantly strengthened the enforcement mechanisms.
In response, the North Korean regime published a message on the official KCNA news agency saying it had cancelled all non-aggression pacts with the South.
The two Koreas have signed a range of agreements over the years, including a 1991 pact on resolving disputes and avoiding military clashes.
However, analysts say the deals have had little practical effect.
The KCNA report detailed other measures including:
cutting off the North-South hotline, saying there was “nothing to talk to the puppet group of traitors about”
closing the main Panmunjom border crossing inside the Demilitarized Zone that separates the two countries
pulling out of the armistice that ended the Korean War.
The North also claimed it had a right to launch a pre-emptive nuclear strike against its enemies.
The threat drew an angry response from South Korea’s defence ministry spokesman Kim Min-seok, who said that the North would become “extinct from the Earth by the will of mankind” if it took such an action.
The US state department said such “extreme rhetoric” was not unusual, but said the US was well protected.
North Korea has breached agreements before and withdrawing from them does not necessarily mean war, but it does signal a more unpredictable and unstable situation.
The United States and China have reached a tentative deal on a new sanctions resolution to punish North Korea for its nuclear test, according to UN diplomats.
Unnamed diplomats said a deal was agreed late on Monday and they hoped a draft resolution would be put to the Security Council on Tuesday.
The details of what has been agreed have not been announced.
North Korea carried out its third and most powerful nuclear test in February, sparking worldwide condemnation.
It was the first such test under new leader Kim Jong-un, who took over the leadership after his father Kim Jong-il died in December 2011.
Pyongyang said the nuclear test was a “self-defensive measure” made necessary by the “continued hostility” of the US.
Nuclear test monitors based in Vienna say the underground explosion had double the force of the last test, in 2009, despite the use of a device said by the North to be smaller.
The US and China have reached a tentative deal on a new sanctions resolution to punish North Korea for its nuclear test
North Korea claimed that a “miniaturized” device had been tested, increasing fears that Pyongyang had moved closer to building a warhead small enough to arm a missile.
The test came weeks after Pyongyang successfully used a rocket to put a satellite into space, a move condemned by the UN as a banned test of missile technology.
China is North Korea’s only ally and its major trading partner. Beijing has been reluctant to support tougher sanctions in the past, citing the impact of potential instability inside its secretive neighbor state. With the recent test, however, its stance appears to have changed somewhat.
A UN diplomat told AFP there had been “tough talks” between China and the US on the issue and that a vote on the draft would happen “soon”, though it was unlikely to be at Tuesday’s session.
Another diplomat told Reuters that whether a draft was circulated on Tuesday was “up to the Americans”.
The UN press office said Russia, which this month holds the presidency at the Security Council, would hold closed-doors talks on Tuesday morning.
North Korea is already subject to a raft of sanctions affecting individuals and government bodies, restricting financial activities and barring any trade or test of ballistics and nuclear technology.
A new North Korean propaganda video posted on YouTube has portrayed President Barack Obama and American troops in flames and says the country conducted its recent nuclear test because of U.S. hostility.
The video, posted on Sunday, follows a string of critical rhetoric against the United States.
Another video posted earlier this month showed an American city, with similarities to New York, being attacked by missiles.
The most recent video was posted by a YouTube account affiliated with a pro-reunification government agency, shows a blazing fire superimposed over footage of Barack Obama.
The video ends with a generic simulation of a nuclear device exploding underground, appearing to refer to North Korea’s recent nuclear test.
The U.S. currently is negotiating in the Security Council for stronger U.N. sanctions against Pyongyang following a February 12 nuclear test in the far northeast, the country’s third since 2006.
Pyongyang released the clip on Uriminzokkiri – Korean for “Our Nation” – which distributes new and propaganda.
A new North Korean propaganda video posted on YouTube has portrayed President Barack Obama and American troops in flames and says the country conducted its recent nuclear test because of U.S. hostility
According to the Global Post, the backing track to the clip comes from a video gamed, Elder Scrolls Oblivion.
North Korea has said the aim of the nuclear test was to bolster its defenses in the wake the hostility of the U.S., which is pushing for sanctions on North Korea.
The country has already told key ally China that it is prepared to stage one or two more tests this year to force the United States into diplomatic talks, a source said.
North Korea also warned its neighbor South Korea on Tuesday that it faces “final destruction” as it took part in a UN conference on disarmament.
U.S. Ambassador Laura Kennedy said she found North Korea’s threat profoundly disturbing and later tweeted that it was “offensive”.
US experts say North Korea appears to be upgrading one of its two rocket launch sites, perhaps in a move to test bigger rockets.
“Important progress” had been made at Tonghae Satellite Launching Ground since October 2012, the analysis from the 38 North website said.
Activities around the new launch pad also revealed possible evidence of assistance from Iran, it said.
Pyongyang used a three-stage rocket to put a satellite into space last year.
That launch – condemned by the UN as a banned test of missile technology – took place at the Sohae launch site.
But previous unsuccessful attempts in 2006 and 2009 took place at the Tonghae site, which is also known as Musudan-ri.
The analysis from 38 North, the website of the US-Korea Institute at Johns Hopkins School of Advanced International Studies in Baltimore, was based on satellite imagery.
Construction of the new launch pad was continuing, it said, with images showing Pyongyang would be able to test rockets “perhaps three to four times the size of the Unha [launched in December 2012] when construction is completed, possibly in 2016”.
Two new design features were similar to those used at the Semnan Launch Complex in Iran, it said.
The images also confirmed activity at the old launch pad.
US experts say North Korea appears to be upgrading one of its two rocket launch sites, perhaps in a move to test bigger rockets
“That activity may be related to another round of modifications intended to support future launches of the Unha rocket or possibly another liquid-fuelled missile,” 38 North said, while cautioning that more information was needed.
North Korea last week conducted its third nuclear test, claiming to have successfully detonated a smaller but more powerful device than in previous tests.
The move drew immediate condemnation from the UN Security Council.
Observers fear North Korea is working towards creating a nuclear device small enough to fit on a long-range missile.
Outgoing Pentagon chief Leon Panetta has declared today that North Korean military ambitions are a “serious threat” to the US.
In a speech made after Pyongyang carried out its third nuclear test, Leon Panetta likened the North to Iran, describing them as “rogue states”.
In New York, the UN Security Council “strongly condemned” the nuclear test.
The council said it would begin work on measures against North Korea, after UN chief Ban Ki-moon said the test was a “clear and grave violation”.
Earlier, Pyongyang said “even stronger” action might follow, saying its test was a response to US “hostility”.
Nuclear test monitors in Vienna say the underground explosion had double the force of the last test, in 2009, despite the use of a device said by the North to be smaller.
If a smaller device was indeed tested, analysts said this could take Pyongyang closer to building a warhead small enough to arm a missile.
UN sanctions on North Korea were expanded after the secretive communist state launched a rocket in December, in a move condemned by the UN as a banned test of missile technology.
North Korea’s latest nuclear test comes as senators in Washington prepare for the first votes on whether to confirm Chuck Hagel as successor to current Defence Secretary Leon Panetta.
In a farewell speech at the Pentagon, Leon Panetta said the US would continue to be tested by unpredictable regimes in years to come.
“We’re going to have to deal with weapons of mass destruction and the proliferation. We’re going to have to continue with rogue states like Iran and North Korea.
“We just saw what North Korea’s done in these last few weeks – a missile test and now a nuclear test. They represent a serious threat to the United States of America. We’ve got to be prepared to deal with that.”
Outgoing Pentagon chief Leon Panetta has declared today that North Korean military ambitions are a “serious threat” to the US
President Barack Obama, who is to make his State of the Union speech later, called the test a “highly provocative act” and called for “swift” and “credible” international action in response.
China, North Korea’s main ally and a veto-wielding member of the Security Council, summoned North Korea’s ambassador to Beijing to express its concern over the test.
Foreign Minister Yang Jiechi delivered a “stern representation”‘ to Ji Jae Ryong and expressed China’s “strong dissatisfaction and firm opposition” to the test, the Chinese foreign ministry said in a statement.
Earlier, it urged the North to honor its commitment to denuclearization and “not take any actions which might worsen the situation”.
The test was condemned by North Korea’s immediate neighbors, South Korea and Japan, while Russian Foreign Minister Sergei Lavrov called for a revival of talks on the North’s nuclear arms programme.
In a defiant message to the UN’s disarmament forum, the North said it would never bow to resolutions on its nuclear programme and blamed the failure of diplomacy on the US.
“The US and their followers are sadly mistaken if they miscalculate the DPRK [North Korea] would respect the entirely unreasonable resolutions against it,” the North’s envoy, Jon Yong Ryong, told the Conference on Disarmament in Geneva.
North Korea confirmed the test after international monitors recorded seismic activity consistent with a powerful underground explosion at 11:57 on Tuesday.
Activity had been observed at the Punggye-ri nuclear test site for several months.
State-run KCNA news agency said the test was “carried out at a high level in a safe and perfect manner using a miniaturized and lighter nuclear device with greater explosive force than previously”.
North Korea said the nuclear test was a response to the “reckless hostility of the United States”.
“The latest nuclear test was only the first action, with which we exercised as much self-restraint as possible,” the foreign ministry said in a statement.
“If the US further complicates the situation with continued hostility, we will be left with no choice but to take even stronger second or third rounds of action.”
The Vienna-based Comprehensive Nuclear-Test-Ban Treaty Organization said the “explosion-like event” was twice as big as the 2009 test, which was in turn bigger than that in 2006.
It is the first such test under new leader Kim Jong-un, who took over the leadership after his father Kim Jong-il died in December 2011.
The US and South Korea warned North Korea of “further consequences” if it carried out a third nuclear test, as Lee Myung-bak, South Korea’s outgoing leader, suggested more than one test could be planned.
Lee Myung-bak, who leaves office later this month, told the Choson Ilbo that Pyongyang could be planning “multiple nuclear tests at two places or more”.
North Korea said in January it was planning a “high-level nuclear test”.
It has conducted two nuclear tests before, in 2006 and 2009.
Both followed the launch of long-range rockets, actions condemned by the UN as banned tests of missile technology.
Pyongyang has given no timeframe for the test, but analysts say satellite imagery indicates preparations at the test site in Punggye-ri are almost complete, with a tunnel in the mountainside apparently being sealed up, a key step before the test can take place.
On Sunday, North Korean leader Kim Jong-un issued what were described as “important” guidelines at high-level government meeting, another indication that the test is imminent.
The Washington-based Institute of Science and International Security has said that although recent satellite images “do not reveal whether a test is imminent, the on-going activity at the site justifies concern that a test will soon occur”.
In a phone call on Monday, the new US Secretary of State John Kerry and his South Korean counterpart Kim Sung-hwan agreed that if North Korea “continues its provocative behavior and takes further steps, that there must be further consequences”, State Department spokeswoman Victoria Nuland told reporters.
The US and South Korea warned North Korea of “further consequences” if it carried out a third nuclear test
The UN Security Council agreed in January to increase sanctions against North Korea after it carried out a long-range rocket launch in December. It also warned Pyongyang it would face “significant action” if the planned nuclear test went ahead.
But Lee Myung-bak said it would be “difficult to persuade the North regime to give up the nuclear path”, and that North Korea’s reference to a “high-level” test could indicate it planned to detonate more than one device.
A test could also bring the country closer to miniaturization of nuclear weapons, a key marker in turning nuclear devices into deployable weapons.
“If the North produces miniaturized weapons that can be used as warheads on missiles, it would really pose a threat,” Lee Myung-bak told the Chosun Ilbo newspaper. “That’s why the whole world is watching it so intensively.”
North Korea watchers have previously said that analysis of the test site indicates two tests could be being prepared.
The country’s two previous tests have both involved plutonium devices, but some analysts say the threat of “high-level” testing could also indicate the North intends to detonate its first nuclear device made with highly-enriched uranium.
North Korea has announced it is proceeding with plans for a third nuclear test.
In a statement carried by KCNA news agency, the top military body said the “high-level nuclear test” and more long-range rocket launches were aimed at its “arch-enemy”, the US.
The statement gave no time-frame for the test. North Korea has conducted two nuclear tests, in 2006 and 2009.
The move comes two days after a UN Security Council resolution condemned Pyongyang’s recent rocket launch.
The Security Council also expanded sanctions against the communist country following its December launch, which was seen by the US and North Korea’s neighbors as a banned test of long-range missile technology.
North Korea said the rocket was solely aimed at putting a satellite into space for peaceful purposes.
The statement, which came from North Korea’s National Defence Commission, hit out at the resolution as “illegal”, before pledging a response.
“We do not hide that the various satellites and long-range rockets we will continue to launch, as well as the high-level nuclear test we will proceed with, are aimed at our arch-enemy, the United States,” KCNA quoted it as saying.
“Settling accounts with the US needs to be done with force, not with words,” it added.
North Korea has announced it is proceeding with plans for a third nuclear test
Recent reports from South Korean and US bodies which monitor North Korea’s nuclear test sites had said North Korea could be preparing for a third test.
Earlier on Thursday, a South Korean defence ministry spokesman said it appeared that North Korea was “ready to conduct a nuclear test at anytime if its leadership decides to go ahead”.
Regional neighbors, South Korea, China and Japan, and the US have urged it not to proceed.
“We hope they don’t do it, we call on them not to do it. It will be a mistake and a missed opportunity if they were to do it,” said Glyn Davies, the US special envoy on North Korea policy who is currently visiting Seoul.
“This is not a moment to increase tensions on the Korean Peninsula.”
A South Korean foreign ministry spokesman said Seoul deeply regretted the North Korean statement and “strongly” urged it not to go ahead.
Both North Korea’s previous nuclear tests followed long-range rocket launches.
If it were to go ahead, this would be the first nuclear test under Kim Jong-un, who took over the leadership after the death of his father Kim Jong-il in December 2011.
There was no explanation in the statement of what “high-level” test might mean.
Experts believe the two previous tests used plutonium as fissile material, but North Korea is also believed to have been working on a programme to produce highly-enriched uranium.
It is thought that North Korea is not yet able to make a nuclear device small enough to mount on a long-range missile, although the US believes that is Pyongyang’s ultimate goal.
North Korean nuclear tests:
Two underground nuclear tests have been carried out by North Korea, in 2006 and 2009
They were believed to have used plutonium, but experts believe the planned test could use highly-enriched uranium as the fissile material
Analysts say a new test tunnel has been prepared in Punggye-ri, the site of the previous tests
North Korea is thought to have enough nuclear material for a small number of bombs, but not the technology to make a nuclear warhead
Multiple rounds of multi-national talks have failed to categorically convince Pyongyang to commit to giving up its nuclear ambitions
Alex Wellerstein, a historian of science at the American Institute of Physics, has shared a unique video of a blast during America’s testing of nukes in the Yucca Mountain area of Nevada during the 1950s.
The historian was sent the video below from a Russian colleague, and has now shared it on his blog.
Alex Wellerstein wrote: “Most films of nuclear explosions are dubbed. If they do contain an actual audio recording of the test blast itself (something I’m often suspicious of – I suspect many were filmed silently and have a stock blast sound effect), it’s almost always shifted in time so that the explosion and the sound of the blast wave are simultaneous.
“This is, of course, quite false: the speed of light is much faster than the speed of sound, and the cameras are kept a very healthy distance from the test itself, so in reality the blast wave comes half a minute or so after the explosion. Basic physics that even a non-technical guy like me can understand.
“It’s rare to find footage where the sound has not been monkeyed with in post-processing. So I was pleased when a Russian correspondent sent me a link to footage digitized by the National Archives of a 1953 nuclear test. The footage is very raw: it hasn’t been edited much, and is a bit washed out, but the audio is still in <<correct>>, original sync.”
Atom blast at Yucca Flat, Nevada, March 17, 1953
Civilians were allowed to watch this blast from 11 miles away, partly an attempt by the government to allay public fears about the dangers of nuclear fallout.
Alex Wellerstein adds: “The audio is what makes this great. Put on some headphones and listen to it all the way through – it’s much more intimate than any other test film I’ve seen. Troops were also on hand, and they can be heard shouting <<Whoa>> and <<Jeez!>> at the end of the video.
“You get a much better sense of what these things must have been like, on the ground, as an observer, than from your standard montage of blasts.
“Murmurs in anticipation; the slow countdown over a megaphone; the reaction at the flash of the bomb; and finally – a sharp bang, followed by a long, thundering growl. That’s the sound of the bomb.
“There were U.S. troops there as well, as part of Operation Desert Rock V. They provide a huge amount of ambient noise.”
Chinese President Hu Jintao pledged strong ties with North Korea, amid serious tensions between the two Koreas in the wake of Pyongyang’s failed rocket launch.
Hu Jintao’s promise came at a meeting with a Workers’ Party delegation headed by Kim Yong-Il in Beijing on Monday.
It came as North Korea threatened “unprecedented action” against Seoul.
Meanwhile the US says it has raised allegations with China that a missile launcher seen in Pyongyang last week was of Chinese origin.
Tension on the Korean peninsula is high following the failed rocket launch on 13 April. Pyongyang said it was putting a satellite into orbit but critics said the launch was a disguised test of missile technology banned under UN resolutions.
US has raised allegations with China that a missile launcher seen in Pyongyang last week was of Chinese origin
South Korea also says there are signs that North Korea may be planning a third nuclear test.
China – which is North Korea’s closest ally and biggest trading partner – did not block UN condemnation of the launch.
But in the meeting on Monday with the Workers’ Party international relations chief, President Hu Jintao emphasized close ties between the two nations.
“We will carry on this tradition… boost strategic communication and coordination on key international issues and work for peace and stability on the Korean peninsula,” state television quoted him as saying.
China – seen as the country with the greatest degree of influence over North Korea – has repeatedly called for calm on the Korean peninsula, as tensions between the two Koreas have risen.
On Monday North Korea warned of “unprecedented” action against South Korea’s ruling establishment, in response to its criticism of the rocket launch.
A special operation to begin “soon” would “reduce its target to ashes”, the North Korean military said in an unusually strong statement. On Friday North Korea also held a rally calling for the death of South Korea’s president.
South Korea, meanwhile, said last week it had deployed new missiles capable of hitting any target in North Korea.
Meanwhile, White House spokesman Jay Carney said in a briefing on Monday that Washington had raised questions over a mobile missile launch vehicle seen in a North Korean military parade earlier this month.
Analysts believe that the 16-wheel missile transporter-erector-launcher (TEL) seen carrying what appeared to be a new missile may have been of Chinese origin.
Last week Jane’s Defence Weekly, citing an unnamed official, reported that the UN Security Council was investigating the claims.
If it had supplied the technology or vehicle, China could be violating UN resolutions passed after North Korean nuclear and missile tests in 2006 and 2009, the report suggested.
Asked about the matter, White House spokesman Jay Carney said the US would “continue to work with the international community, including China, to enforce sanctions against North Korea’s ballistic missile program and nuclear programme”.
“We’ve raised the allegations with the Chinese government … as part of our ongoing close consultations on North Korea,” he said.
China says it has abided by UN sanctions on North Korea.