Obama's passive performance in their first debate two weeks ago, and Romney's subsequent surge in the polls, have raised expectations for a more fiery encounter at New York's Hofstra University.

Obama's team has been encouraged by the feisty performance of Vice-President Joe Biden last week in his debate against Republican vice-presidential nominee Paul Ryan.

With Romney having virtually erased Obama's lead in national polls three weeks before the November 6 election, Obama is hoping to take advantage of the town hall-style format of today's debate to make a direct pitch to the voters. He is likely to propound his economic vision, which focuses on a tax breaks for the middle class and tax increases for the wealthy.

Romney has called for across-the-board tax cuts. He sparred with Obama over whether his plan would add to the US's debt problems.

On Sunday, Reuters/Ipsos surveys of likely voters indicated that Romney had closed the gap, or overtaken Obama, in the past two weeks on a range of issues, including creating jobs, taxes and Iran's nuclear ambitions.

Though the US unemployment rate dipped below 8% last month for the first time since Obama took office in January 2009, Romney now leads the incumbent by 42.5% to 39.2% among likely voters on the question of who would be better at creating jobs.