COPENHAGEN - The $10 billion a year proposed by rich nations to help the poor adapt to climate change is "not much, it's not sufficient," and the gap between what's offered and what's needed could wreck the Copenhagen climate conference, American billionaire George Soros said Thursday.

The investor-philanthropist, one in a line of international notables visiting the 192-nation meeting, told reporters he had developed a partial solution. Soros suggested shifting some International Monetary Fund resources from providing liquidity to stressed global financial system to a new mission of financing projects in developing countries for clean energy and adapting to climate change.

About $100 billion in a one-time infusion could be generated, said Soros, a major supporter of causes in the developing world.

But he acknowledged a roadblock in Washington.

"It is possible to substantially increase the amount available to fight global warming in the developing world," he said. "All that is lacking is the political will. Unfortunately the political will will be difficult to gather because of the mere fact that it requires congressional approval in the United States."

Soros said he had "informal discussions" with Obama administration officials and "the difficulty of getting congressional approval has been recognized."

The international financier dropped in on the two-week conference on its fourth day, as rich and poor nations pressed on behind closed doors and in open forums to bridge wide differences and reach agreements on how to combat global warming.

They have just a week to deliver something for President Barack Obama and more than 100 national leaders to sign in the finale of the Copenhagen climate summit on Dec. 18.