Washington - US President George W Bush Fridady pledged that the US government will tackle the root of the financial turmoil through a massive intervention that could cost hundreds of billions of dollars.

Bush said a comprehensive plan was crucial to keeping the financial sector from total collapse and freezing the availability of credit to US consumers.

"The American economy is facing unprecedented challenges. We are responding with unprecedented action," Bush said in remarks broadcast from the White House.

He was flanked by his top finance chiefs Treasury Secretary Henry Paulson, Federal Reserve Chairman Ben Bernanke and Securities and Exchange Commission chairman Christopher Cox.

"This is a pivotal moment for America's economy," Bush said. "There will be ample opportunity to debate the origins of this problem, now is the time to solve it."

Bush said the intervention would require a "significant amount of taxpayer dollars." Paulson earlier said the cost would be in the "hundreds of billions."

Few exact details of the plan have been revealed. The details are expected to be worked out with Congress over the weekend.

The plan essentially involves creating a new government agency that could soak up all the bad assets that are bringing down US financial firms.

Bush said he was confident the mortgage-backed securities, which the government is now taking on, would recover their value in the longer term. Their value has plunged due to a record rate of home foreclosures in the US, but Bush pointed out that most Americans still paid their mortgages on time. (dpa)