Berlin - The US economy needs 300-600 billion dollars in additional support measures to help it weather the financial crisis, billionaire George Soros was quoted as saying by German news magazine Der Spiegel on Saturday.

"A major stimulus programme" was needed to help the ailing economy and provide US cities and states with sufficient cash, said Soros, one of the world's richest men. In addition, an infrastructure programme was needed, he said.

The US has already announced a 700 billion-dollar bailout in response to the crisis, which Soros said had "surpassed my wildest expectations."

Financial markets were under a lot of pressure because the US is in a difficult phase of transition from one administration to next, he told the magazine in an interview due for publication on Sunday.

Soros said he had high hopes president-elect Barack Obama would take the appropriate measures after he assumes office in January.

"The duration of the crisis depends on the success of his policies," he said quoted as saying.

The financier criticized US Treasury Secretary Henry Paulson, saying he was "totally unprepared" when investment bankers Lehman Brothers went bankrupt, sending financial markets into a tailspin.

"He reacted to the problems after they arose. He did not have the ability to see these problems coming," Soros said. (dpa)