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. The fact that the G20 has usurped the G8 as the main forum for discussing the crisis already illustrates a shift in the economic and diplomatic landscape with the emergence of India, Brazil and, particularly, China as major players.

On Wednesday, leaders of major countries called for closer cooperation in dealing with the financial crisis.

Chinese President Hu Jintao (2nd R) talks with British Prime Minister Gorden Brown (R) as they prepare to pose for a family photo during the Group of 20 summit in London, Britain, April 2, 2009. [Xinhua]

Chinese President Hu Jintao said at a meeting with his Russian counterpart Dmitry Medvedev Wednesday that China and Russia should strengthen cooperation to jointly overcome the current difficulties under the complicated and grave conditions of the world economy.

The two countries need to strengthen communication and consultation, coordinate their stands within the G20 framework in particular, and push forward reforms of the international financial system, Hu said.

U.S. and British leaders voiced optimism that the G20 summit will reach consensus on concerted efforts to deal with major issues.

"I am absolutely confident that this meeting will reflect enormous consensus about the need to work in concert to deal with these problems," said U.S. President Barack Obama after talks with British Prime Minister Gordon Brown on Wednesday.

German Chancellor Angela Merkel and French President Sarkozy Wednesday called for concrete actions at the Group of 20 (G20) , warning that those who do not abide by the G20 commitments must be singled out.

United States President Barack Obama (R) arrives at ExCel center and is greeted by British Prime Minister Gordon Brown for the summit of the Group of 20 Countries (G20) in London April 2, 2009.[Xinhua]

Speaking at a joint press conference following their meeting in London one day ahead of the summit, Sarkozy said bank loans need to be traceable, funds needs to be registered and checked, adding that the aim of agreeing on new regulations for the financial sector is "non-negotiable."

The two leaders demanded that a new regulation of the international financial system be set up. "Without a new regulation ,there will be no trust. And without trust, there will be no recovery. It is a major objective, non-negotiable," said Sarkozy.

Merkel said that "more regulation is necessary" for the world to get out of the crisis.