Washington - A presidential debate planned to address foreign policy started Friday with a discussion of the ongoing US financial crisis and attempts in Washington to hammer out a rescue plan.

Senator Barack Obama, 47, the nominee of the centre-left Democratic Party, called the current time "a defining moment in our history" with ongoing wars in Iraq and Afghanistan and the worst financial crisis since the Great Depression.

"We have to move swiftly, but we have to move wisely," he said.

He said that the 700-billion-dollar bailout package being negotiated over the weekend in Congress must contain oversight to protect taxpayers, with the federal government expected to buy up soured mortgage-based securities and other so-called "toxic" assets, which have contributed to a sharp slowdown in credit markets.

Obama insisted that the final package to rescue the financial sector make sure that executives of struggling companies do not profit from government help, while the measure should find a way to assist homeowners struggling to pay their mortgages.

He called the current crisis a "final verdict" on the eight-year administration of President George W Bush, who leaves office on January 20. Obama accused his major-party opponent, Senator John McCain, 72, of supporting the policies of Bush, who has the worst approval ratings of any president in more than 30 years.

McCain, presidential nominee of Bush's centre-right Republican Party, said that Republicans and Democrats in Congress were seeking to reach a bipartisan consensus on the resue package "as we're here tonight."

He called for consolidation of regulatory agencies that failed to prevent the current crisis on Wall Street and said that it was vital to "get spending under control in Washington," touting his record of opposing wasteful use of tax money and suggesting that a freeze of spending for most federal programmes would be a good idea.

He voiced faith that US workers could rally the struggling economy.

"I still believe, under the right leadership, our best days are ahead of us," McCain said.

Friday's debate was the first of three planned before the November 4 general elections. (dpa)