The International Monetary Fund head said such companies “will use their enormous customer bases and deep pockets to offer financial products based on big data and artificial intelligence”.
“This presents a unique systemic challenge to financial stability and efficiency,” she added.
Christine Lagarde cited China as a most recent example.
She said: “Over the last five years, technology growth in China has been extremely successful and allowed millions of new entrants to benefit from access to financial products and the creation of high-quality jobs.
“But it has also led to two firms controlling more than 90% of the mobile payments market.”
On November 29, President Poroshenko announced that Russians living in Ukraine would soon face restrictions on bank withdrawals, changing foreign currency and travelling abroad.
The incident happened on November 25, when two Ukrainian gunboats and a tug were sailing from Odessa to the port of Mariupol, in the Sea of Azov – which is shared between Russia and Ukraine.
The ships were stopped from entering the Kerch Strait and confronted by FSB border guards. After a lengthy standoff, during which the Ukrainian tug was rammed, the vessels began turning back towards Odessa, the Ukrainian government says.
The Russians opened fire, wounding at least three sailors, and seized the Ukrainian flotilla.
The Kerch Strait separates Russia from Crimea, a Ukrainian peninsula that was annexed by Russia in 2014.
However, Ukraine says Russia is deliberately blockading Mariupol and another Ukrainian port on the Sea of Azov, Berdyansk.
The 24 captured Ukrainian sailors have now been given two months in pre-trial detention by a court in Crimea.
G20 leaders at Saint Petersburg summit remain divided over the Syrian conflict as they enter the final day of their meeting.
Italian PM Enrico Letta said the splits were confirmed during a working dinner in St Petersburg on Thursday.
A spokesman for the Russian presidency said a US strike on Syria would “drive another nail into the coffin of international law”.
At the UN, the US Ambassador Samantha Power accused Russia of holding the Security Council hostage by blocking resolutions.
Samantha Power said the Security Council was no longer a “viable path” for holding Syria accountable for war crimes.
The US government accuses President Bashar al-Assad’s forces of killing 1,429 people in a poison-gas attack in the Damascus suburbs on August 21.
The UK says scientists at the Porton Down research laboratories have found traces of sarin gas on cloth and soil samples.
But Bashar al-Assad has blamed rebels for the attack. China and Russia, which have refused to agree to a Security Council resolution against Syria, insist any action without the UN would be illegal.
The US and France are the only nations at the G20 summit to commit to using force in Syria.
Samantha Power told a news conference in New York: “Even in the wake of the flagrant shattering of the international norm against chemical weapons use, Russia continues to hold the council hostage and shirk its international responsibilities.
G20 leaders at Saint Petersburg summit remain divided over the Syrian conflict as they enter the final day of their meeting
“What we have learned, what the Syrian people have learned, is that the Security Council the world needs to deal with this crisis is not the Security Council we have.”
President Barack Obama is thought to be trying at the G20 summit to build an international coalition to back strikes against military targets in Syria.
But differences of opinion became obvious when world leaders – including Barack Obama and Russian President Vladimir Putin – discussed Syria over dinner on Thursday evening.
Enrico Letta said in a tweet that “the G20 has just now finished the dinner session, at which the divisions about Syria were confirmed”.
President Vladimir Putin’s press spokesman, Dmitry Peskov, said after the dinner that the G20 was split down the middle, with some countries seeking hasty action and others wanting the US to go through the UN Security Council.
British sources say the leaders of France, Turkey, Canada and the UK gave strong backing to President Barack Obama’s call for military action. The UK Chancellor of the Exchequer George Osborne said the Turks put a “very strong argument about how the world must respond to the use of chemical weapons”.
But correspondents in St Petersburg say opponents of US military intervention appear to far outnumber supporters within the G20.
However, the views of the G20 leaders on any US action could be the least of Barack Obama’s worries, as his real difficulties might lie back in the US.
He was nearly an hour late for Thursday’s G20 dinner. His aides said he had been trying to find time during the summit to call US members of Congress, who are due to vote next week on whether to back Barack Obama’s call for a military strike.
President Barack Obama also cancelled a trip to California on Monday in order to lobby Congress, as a poll commissioned by the BBC and ABC News suggested more than one-third of Congress members were undecided whether or not to back military action.
A majority of those who had made a decision said they would vote against the president.
Syria’s parliamentary speaker has written to the speaker of the House of Representatives urging members not to rush into an “irresponsible, reckless action”.
The Assad regime has been accused of using chemical weapons against Syrian civilians on several occasions during the 30-month conflict.
Some 100,000 people have died in the conflict, and more than two million Syrians are classified as refugees, according to the UN.
US diplomats are reportedly having secret talks with their Russian counterparts behind the scenes at the G-20 summit in St. Petersburg in hopes of avoiding a stalemate over Syria.
Moscow publicly warned that a military strike on Syria could have catastrophic effects if a missile hit a small reactor near Damascus that contains radioactive uranium.
The talks started last week and are continuing both in Russia and New York, said the source, who spoke on condition of anonymity because he is not authorized to speak publicly about bilateral diplomatic talks.
Russia is insisting that Barack Obama call off a planned military strike against Syria if either house of Congress declines to authorize it.
Meanwhile, US diplomats are insisting that the Russians bend in the opposite direction. They want Vladimir Putin’s government to entertain seriously a proposal from Saudi Arabia, which would require them to refrain from opposing UN Security Council resolutions pertaining to Syria and wind down its arms sales to Bashar al-Assad’s regime.
Vladimir Putin is insisting that Barack Obama call off a planned military strike against Syria if either house of Congress declines to authorize it
Russia urged the UN International Atomic Energy Agency (IAEA) secretariat to “react swiftly” and present IAEA members “an analysis of the risks linked to possible American strikes on the MNSR and other facilities in Syria”.
Moscow has been the most powerful ally of Syrian President Bashar al-Assad, shielding him from tougher UN resolutions and warning that a Western military attack on Syria would raise tensions and undermine efforts to end the country’s civil war.
“The IAEA is aware of the statement but has not received a formal request from the Russian Federation,” an IAEA spokesperson said.
“We will consider the questions raised if we receive such a request.”
The IAEA said in a report to member states last week that Syria had declared there was a “small amount of nuclear material” at the MNSR, a type of research reactor usually fuelled by highly enriched uranium.
The seating plan at today’s G20 summit in Saint Petersburg, Russia, has reportedly been adjusted to put physical distance between host President Vladimir Putin and President Barack Obama as tensions are running high over Syria.
Ahead of the meeting of the leading world economies in St Petersburg, Vladimir Putin warned that action without UN approval would be “an aggression” as the relationship between the two countries reaches its lowest point since the Cold War.
But President Obama, who is leading the international drive for an armed response to Syrian President Bashar al-Assad’s apparent breach of the prohibition on the use of chemical weapons, said the credibility of the international community was on the line.
The seating plan at G20 summit in Saint Petersburg has been adjusted to put physical distance between host Vladimir Putin and Barack Obama
Barack Obama last night cleared the first hurdle to obtaining Congressional approval for a strike, as the influential Senate Foreign Affairs Committee backed the use of force by a margin of 10-7, moving the measure to a full Senate vote next week.
The proposal allows the use of force for 60 days, with the possibility of a 30-day extension.
He president has said he is confident of receiving approval from Congress for “limited and proportionate’ military action, which he said would not involve US troops putting ‘boots on the ground” in Syria.
Bashar al-Assad had flouted a chemical weapons ban enshrined in treaties signed by governments representing 98% of the world’s population, he said, adding: “I didn’t set a red line. The world set a red line.”
Speaking in Sweden as he travelled to St Petersburg, Barack Obama said the credibility of the international community was “on the line” if it allowed Bashar al-Assad to act with impunity.
G20 leaders are meeting in Sankt Petersburg, Russia, amid sharp differences over the crisis in Syria.
US President Barack Obama has begun informal talks with other leaders as he pushes for military action over Syria’s alleged use of chemical weapons.
But Russian President Vladimir Putin has warned that military action without UN approval would be “an aggression”.
Syria is not officially on the G20 agenda in St Petersburg, but it is expected to dominate informal meetings.
The annual summit of the G20 group of the world’s leading economies is supposed to concentrate on the global economy.
Barack Obama, British PM David Cameron and Chinese President Xi Jinping are among the leaders who have now arrived at the G20.
On Thursday the medical charity Medecins Sans Frontieres (MSF) said one of its surgeons, a Syrian working in Aleppo province, had been killed.
It gave no details of the circumstances but called for humanitarian workers to be protected.
Separately, Syrian rebels have launched an assault on the religiously mixed village of Maaloula, in western Syria, held by government forces.
A Christian nun in Maaloula told the Associated Press news agency that the rebels had seized a mountain-top hotel and were shelling the community below.
On the eve of the summit, a US Senate panel approved the use of military force in Syria, in response to an alleged chemical weapons attack.
G20 leaders are meeting in Sankt Petersburg amid sharp differences over the crisis in Syria
The proposal, which now goes to a full Senate vote next week, allows the use of force in Syria for 60 days with the possibility to extend it for 30 days.
The measure must also be approved by the US House of Representatives.
The Damascus government is accused of using chemical weapons against civilians on several occasions during the 30-month conflict – most recently on a large scale in an attack on 21 August on the outskirts of the capital.
The government of Syrian President Bashar al-Assad has denied involvement and said the rebels were responsible.
The US has put the death toll from that incident at 1,429 – though other countries and groups have given lower figures – and says all the evidence implicates government forces.
Vladimir Putin dismissed as “ludicrous” claims the Syrian government used chemical weapons, but said Russia would be ready to act if there was clear proof of what weapons were used and by whom.
Barack Obama is trying to build support in the US for military action against the Syrian government.
After arriving in St Petersburg, he held talks with Japanese PM Shinzo Abe in the first of a series of meetings on the sidelines.
Barack Obama said Japan and the US had a “joint recognition” that the use of chemical weapons in Syria was a tragedy and a violation of international law.
Shinzo Abe has not stated publicly whether he supports military strikes.
A new study of images apparently from the chemical attack on August 21 concludes that the rockets carrying the gas held up to 50 times more nerve agent than previously estimated, the New York Times reported.
The study was carried out by an expert in warhead design, Richard Lloyd, and Theodore Postol, a physicist at the Massachusetts Institute of Technology.
The German intelligence service, the BND, told German MPs in a confidential briefing on Wednesday that Syrian forces might have misjudged the mix of gases in the attack, the German magazine Der Spiegel reported.
This might explain why the death toll was much higher than in previous suspected attacks, the head of the BND was quoted as saying.
France has strongly backed the US plan for military action. The French parliament debated the issue on Wednesday, although no vote was held.
The United Nations says more than 100,000 people have been killed since the uprising against Bashar al-Assad began in March 2011.
More than two million Syrians are now registered as refugees, the UN says, with an additional 4.25 million displaced within the country, making it the worst refugee crisis since the 1994 genocide in Rwanda.
World leaders meeting at a G20 summit in Mexico have urged Europe to take all necessary measures to overcome the eurozone debt crisis.
They voiced unease over what one top official described as “the single biggest risk for the world economy”.
But European Commission President Jose Manuel Barroso said “the challenges are not only European, they are global”.
Sunday’s victory of a pro-bailout party in the Greek election did not give stock markets the expected boost.
Antonis Samaras, the leader of the New Democracy party that narrowly won the poll, is holding urgent talks to form a coalition.
Antonis Samaras also reiterated that he would seek changes in the terms of a bailout agreement reached with the EU and IMF.
While Europe is clearly the big danger, there are also problems elsewhere in the world’s major advanced and emerging economies, starting with the two largest national economies, the US and China.
The slowdown in India is something else for the G20 to fret about at the Mexican resort of Los Cabos.
World leaders meeting at a G20 summit in Mexico have urged Europe to take all necessary measures to overcome the eurozone debt crisis
A draft of the statement to be released on Tuesday is expected to call for a coordinated global plan for job creation and growth, reports say.
And if growth weakens, the proposed document says, countries without heavy debts should “stand ready to co-ordinate and implement discretionary fiscal actions to support domestic demand”, according to Reuters.
In a separate development, China pledged $43 billion to the IMF’s crisis-fighting fund.
The move comes after a meeting of the Brics group of emerging economies – Brazil, Russia, India, China and South Africa. The five nations all offered to increase their contributions to the IMF in exchange for greater influence in the organization.
US President Barack Obama and Russian President Vladimir Putin held talks on the sidelines of the summit, urging an immediate end to violence in Syria.
In a joint statement following their first meeting since Vladimir Putin returned to the presidency, they said they shared a belief that Syrians should determine their own future.
The two countries have been at odds over how to resolve the crisis.
On Monday, many world leaders expressed alarm in Los Cabos at what they saw as a lack of progress in dealing with the eurozone crisis.
World Bank chief Robert Zoellick said: “We are waiting for Europe to tell us what it’s going to do.”
Meanwhile, Jose Angel Gurria, the Mexican head of the Organisation for Economic Co-operation and Development (OECD), said the crisis was “the single biggest risk for the world economy”.
Pascal Lamy, the head of the World Trade Organization (WTO), warned about the danger of contagion from the eurozone crisis.
He said that global volatility and uncertainty was fuelling a trend towards protectionism, which was not only stalling free trade but starting to reverse it.
Canadian Prime Minister Stephen Harper called on eurozone leaders to make structural changes to solve the debt crisis.
But Jose Manuel Barroso mounted a strong defense of the EU’s handling of the crisis so far.
“Frankly, we are not coming here to receive lessons in terms of democracy or in terms of how to handle the economy,” he told reporters.
He added that he expected G20 leaders to “speak very clearly in favor of the approach the EU is following”.
Meanwhile, Russian President Vladimir Putin called for rules to allow protectionism for countries facing a financial crisis.
“It is time to stop pretending and come to an honest agreement on the acceptable level of protectionist measures that governments can take to protect jobs in times of global crisis,” he said.
“This is particularly important for Russia as our country will join the WTO this year and we intend to take an active part in the discussions on the future rules for global trade.”
US President Barack Obama had earlier talked about the importance of avoiding protectionism, which is the process of making imports more expensive to protect domestic jobs.