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Republican John McCain said he will attend the first of three presidential debates with Democrat Barack Obama tonight, ending two days of suspense and setting up a showdown that could help decide a tight race for the White House.
Mr McCain had vowed to skip the debate if a $700bn rescue of the US financial industry was not settled, but his campaign said in a statement that enough progress had been made to go ahead.
He will come back to Washington after the event and return to the negotiations.
Debate sponsors had said the show would go on with or without Mr McCain, and Mr Obama was preparing to fly to Mississippi at midday.
The debate is scheduled to focus on foreign policy and national security, although the turmoil on Wall Street has dominated the campaign trail for nearly two weeks and is almost certain to be discussed.
Both candidates spent last night in Washington and conferred with congressional leaders this morning before bailout negotiations resumed.
At the request of President George W Bush, Mr Obama had joined Mr McCain in a White House meeting with congressional leaders yesterday but McCain aides said the meeting 'devolved into a contentious shouting match.'
Senior Democrats said Mr McCain appeared to be backing a different plan than the Bush administration proposal under discussion for days.
Mr McCain aides said he did not endorse any plan and the Obama-led Democrats 'did not seek to craft a bipartisan solution.'
Mr Obama said Mr McCain's decision to return to Washington and participate in the bailout talks had injected a sour dose of presidential politics into the proceedings.
'It's not necessarily as helpful as it needs to be,' the Illinois senator told reporters after the White House meeting. 'There was a lot of glare, the spotlight, there's the potential for posturing or suspicions.'
Mr McCain's decision relieved organisers at the National Commission on Debates and the hosts at the University of Mississippi, which spent about $5m to accommodate the event, and the 3,000 journalists who descended on Oxford to cover it.
The first debate was expected to be watched by far more than the 40m Americans who saw the convention acceptance speeches of Mr McCain and Mr Obama, and could be a crucial factor for undecided voters in the 4 November election.
Public opinion polls have shown Mr Obama making gains over the past week on the question of who could best lead the country on economic issues, and most polls have him holding a slight lead over McCain.
Both camps have worked to lower expectations for their candidates in the high-stakes confrontation.
Obama aides have noted that national security and foreign policy is a strength for Mr McCain, a 26-year veteran of Congress and a former prisoner of war in Vietnam.
Opinion polls show voters favor Mr McCain on security issues.
