In a television address to the nation, US President George W Bush on Wednesday warned the public that the US economy was in danger.

"We are in the midst of a serious financial crisis," he said on Wednesday from the White House's ornate East Room a day before hosting unprecedented crisis talks.

The US President's announcement on the US economy comes as Democratic presidential hopeful Barack Obama said that he would now attend a White House meeting on Thursday on the financial crisis, and stressed that the first 2008 US presidential debate should go ahead as scheduled on Friday.

His Republican rival John McCain had announced the suspension of his presidential campaign on Wednesday over the Wall Street meltdown and called for the debate to be postponed.

He will meet with Bush, Obama and congressional leaders at the White House summit in an attempt to solve the crisis.

"Senator Obama has been working all week with leaders in Congress, (Treasury) Secretary (Henry) Paulson, and (Federal Reserve) chairman (Ben) Bernanke to improve this proposal, and he has said that he will continue to work in a bipartisan spirit and do whatever is necessary to come up with a final solution," said Obama spokesman Bill Burton, after announcing that the Democratic Senator had accepted the Bush invitation.

Obama also "strongly believes the debate should go forward on Friday so that the American people can hear from their next president about how he will lead America forward at this defining moment for our country," Burton said.

The Illinois senator and McCain are scheduled to face off in their first presidential debate in Oxford, Mississippi.

Obama said it was more important than ever to debate the turmoil wracking the US economy, and in a biting rebuke said a president should be able to "deal with more than one thing at once."

McCain's bold gambit came as several new opinion polls showed him falling behind Obama in the presidential race amid evidence that his halting early response to the financial crisis has hurt his prospects.

McCain earlier said that he did not believe the $700 billion Wall Street bailout plan presented by the Bush administration "will pass as it currently stands, and we are running out of time," McCain said, stressing the nation "faces an historic crisis in our financial system."

"We must meet as Americans, not as Democrats or Republicans, and we must meet until this crisis is resolved," the Arizona senator added.

"I am directing my campaign to work with the Obama campaign and the Commission on Presidential Debates to delay Friday night's debate until we have taken action to address this crisis," said McCain.

But Obama shortly afterwards spoke to reporters in Florida and rebuffed McCain's call.

"What I'm planning to do right now is to debate on Friday. My general view is that the American people need to know what it is we intend to do in moving the economy forward," he said.

The Illinois senator said that he had spoken to McCain in the afternoon and had been under impression their staffs were working together on a joint statement adding McCain had told him they should join a bipartisan effort to ease the crisis in Washington.

New polls, meanwhile, suggested a possible Obama surge and hinted that he was profiting from the crisis.

The Washington Post/ABC poll gave Democrat Obama a 52 percent to 43 percent lead.

Obama was up 45 to 39 in a Fox News/Opinion Dynamics survey, but another poll by NBC News and the Wall Street Journal poll put the gap at only two points.