Republican presidential candidate John McCain is to suspend his election campaign to work on a Wall Street rescue plan and is calling for a debate on Friday with Democrat Barack Obama to be postponed.
Senator McCain says he will suspend his campaign to return to Washington and is asking Senator Obama to do the same.
He says now is the time to put politics aside and focus on financial stability and economic recovery.
However, Senator Obama won't agree to postpone the debate. He said it was "more important than ever" for US citizens to hear from the person who would soon be "dealing with this mess".
A Washington Post-ABC News national opinion poll issued on Wednesday put Senator Obama nine points clear of Senator McCain, with 52% support to his 43% among likely voters.
Two weeks ago, polls suggested the two candidates were neck-and-neck.
According to the Washington Post, half of those surveyed said the economy and jobs were the most important issues in deciding their vote, up from 37% a fortnight ago.
The poll suggested Senator Obama had a big edge - 14 points over Senator McCain overall and 21 points among independent voters - as the candidate more in tune with the economic problems voters faced.