United States President Barack Obama and Republican challenger Mitt Romney are approaching the final day of their election battle in a frantic fight for swing state votes.
National polls show the candidates are neck and neck ahead of the presidential election on Tuesday, but polls of many key battlegrounds show Mr Obama narrowly ahead.
The pair spent Sunday addressing crowds throughout the country, with Mr Romney speaking in Pennsylvania - a state his aides insist he can now win, the BBC reports.
Mr Obama held rallies in New Hampshire and Florida and carried on to Ohio and Colorado in the evening.
The campaign has been most intense in Ohio, which no Republican has ever lost and still made it to the White House. The parties have together spent more than $US218 million on television advertisements in the crucial state.
On Monday morning, Mr Obama is scheduled to appear in Madison, Wisconsin, accompanied by singer Bruce Springsteen, before going on to Iowa and Ohio. Mr Romney is due in Florida - where polls suggest he is ahead - in Virginia, New Hampshire and Ohio.
A final poll published on Sunday by Ohio's Columbus Dispatch gave Mr Obama a 2% lead - 50% to 48% - over his rival, within the margin of error.
Mr Romney told crowds in Cleveland that Mr Obama has failed in his pledge to be a "post-partisan" president and criticising his record.
"He's been divisive, blaming, attacking, dividing and - by the way - it's not only Republicans that he refused to listen to, he also refused to listen to independent voices."
Mr Obama made another appearance in Cincinnati, Ohio, where Stevie Wonder opened a huge evening rally. Earlier in the day at a rally in Concord in New Hampshire, Mr Obama said: "We have come too far to turn back now."
The president said he would work across party lines to break the political gridlock in Washington, but would not compromise on priorities such as healthcare and college financial aid.
Another opinion poll for ABC News and the Washington Post on Sunday put the candidates at 48%, with even voters who term themselves independents split evenly on 46%.
Mitt Romney remains favoured among whites, seniors and evangelical Christians; Barack Obama among women, non-whites and young adults. The president also remains slightly ahead in most of the nine-or-so swing states that will determine the election.
The election is run using an electoral college. Each state is given a number of votes based on its population. The candidate who wins 270 electoral college votes becomes president.
Analysts say the election will come down to a handful of swing states.
Disruption to voting
The storm damage from a deadly super-storm is affecting preparations for voting in the election, the BBC reports.
New Jersey residents displaced by Sandy will be able to vote by email or fax, the state's chief election official says.
They will be designated as "overseas voters" and can apply for mail-in ballots up until 5pm local time on election day.