WASHINGTON - PRESIDENT George W. Bush on Friday defended the US government's extraordinary series of interventions in the financial crisis, calling them measures of 'last resort' that will ultimately work to restore the economy to stability.

'I would oppose such measures under ordinary circumstances,' Mr Bush said in a speech timed to wrap up just before Friday's stock market opening. 'But these are not ordinary circumstances.'

He cautioned, as he has repeatedly before, that the government moves were aimed at preventing the problems from growing worse, not as an immediate salve to the battered economy.

'It took a while for the credit markets to freeze up, and it's going to take a while for the credit system to thaw,' Mr Bush said in 20 minutes of remarks delivered across the street from the White House at the US Chamber of Commerce building, a symbolic headquarters of American business.

Seeking to calm markets that have gyrated wildly - and mostly downward - despite massive infusions of government cash into the system, Mr Bush said the steps are 'big enough and bold enough to work'.

'The American people can be confident that they will,' the president said.

The main thrust of his speech, however, seemed aimed at conservatives and members of the public that are wary of so much government intervention into private markets.

He presented himself as a free-market devotee dragged into these moves, which he defended as limited in size, scope and duration. He said there will be strong oversight and perhaps even taxpayer benefit over the long term.

'Had the government not acted, the hole in our financial system would have grown larger,' Mr Bush said. 'We would have been forced to respond with even more drastic and costly measures later on.' -- AP