Details have been emerging of the plan by the US Treasury to stabilise the country's financial system.
The US government is preparing a sweeping bailout to mop up hundreds of billions of dollars in bad mortgage debt.
The plan would not be carried out by a new US Government agency but instead by investment managers specially hired by the treasury to manage a fund of $500-800bn.
Some congressional leaders are believed to be uncomfortable with the idea of tax payers taking on hundreds of billions of dollars of apparently worthless debt.
US President George W Bush has spoken of the need for unprecedented action to meet unprecedented challenges.
He called it a pivotal moment for the US economy.
'Given the precarious state of today's financial markets and their vital importance to the daily lives of the American people, government intervention is not only warranted, it is essential,' Mr Bush said.
Congress to vote soon on plan
A Congress vote is expected within days on the US government plan.
Government officials said they had more work to do. 'We must now take further, decisive action to fundamentally and comprehensively address the root cause of our financial system's stresses,' Treasury Secretary Henry Paulson told a news conference.
'The federal government must implement a programme to remove these illiquid assets that are weighing down our financial institutions and threatening our economy.'
Mr Paulson and Federal Reserve Chairman Ben Bernanke planned to work through the weekend with Congress on the bad debts plan.
Banks worldwide have suffered more than $500bn of write-downs and loan losses since the global credit crisis began more than a year ago.
The crisis grew more acute this month with government takeovers of mortgage companies Fannie Mae and Freddie Mac, the bankruptcy of Lehman Brothers, Merrill Lynch's agreement to be bought by Bank of America and a bailout of insurer AIG.
This came just six months after a government-backed rescue of Bear Stearns.
