Leaders from the Group of 20 nations (G20) are gathering?in London?Wednesday for the crucial summit talks, which aim to reach agreement on revitalizing the global economy and reforming the world financial system.

US President Barack Obama, who arrived late Tuesday, held bilateral talks with British Prime Minister Gordon Brown Wednesday morning.

Speaking at a joint press conference following their meeting at the Downing Street 10, both Obama and Brown said that they agreed that a global solution is needed for the financial crisis.

The two leaders also agreed that there should be more banking regulations. Brown stressed that no recovery takes place until the banks are cleaned up. Obama said:"We have passed the era of irresponsibility."

Referring to the G20 summit, Obama said: "I came here to listen," stressing that the leaders should seek "common ground", "not our differences". He stressed that the differences were "vastly overstated".

The G20 summit is scheduled to begin at the Excel Centre in London's Docklands on Thursday.

The meeting, the second such high-profile gathering since November, is expected to agree to a major revamp of the world financial system as well as new coordinated measures to combat the economic downturn.

But the outcome of the summit rests with participants' ability to bridge their differences on economic stimulus plans and reforming the global financial system.

While the White House has pushed for more fiscal measures to help the economy, major European countries, notably Germany and France, remain sceptical about this and they mainly focus on tightening financial regulation and reforming the world financial system to prevent such a crisis in future.

French President Nicolas Sarkozy reportedly has threatened to walk out of the London summit if his demand for stronger financial regulation were not met.

Speaking in an interview with French radio Europe 1 on Wednesday, Sarkozy reiterated that he wouldn't want to "associate" himself with a G20 that would be concluded by "false compromises."

He said neither France nor Germany is satisfied with the current draft of the G20 statement, which he said should go even further on tightening financial regulations.

"Regulation is at the heart of the debate," Sarkozy said.

Major developing countries also support reforming the world financial system, but they insist that should have a bigger say in multilateral financial discussion and relevant policy-making process.

While the London summit brings together leaders from the top 20 industrialized and emerging economies, the city has also braced itself for a series of massive anti-globalization, anti-war and pro-environmental protests.

Massive security operation is underway in London and police leave has been cancelled, BBC news reported Wedneday, showing live pictures of thousands of protesters waving flags and chanting in front of Bank of England.

Many banks and shops have been boarded up, and city workers are urged to dress down.

(Xinhua News Agency April 1, 2009)