In pictures: US election countdown

On the eve of the United States presidential election, officials across the country are busy setting up polling stations.

Republican candidate John McCain is undertaking an 11th-hour dash across seven states to shore up his support.

He visited several key states, including Pennsylvania, on a whistle stop final day of campaigning.

McCain's running-mate Sarah Palin urged supporters in the swing state of Iowa not to give up the fight, despite trailing in opinion polls.

Democratic candidate Barack Obama is targeting three states on his final day of campaigning - all won by the Republicans in 2004.

He told supporters at a rally in Jacksonville, Florida, that change was just one day away.

Millions of Americans voted early in the election, including in the key state of Ohio.