U.S. President Barack Obama and Republican challenger Mitt Romney are facing off in their second debate.

The two men are taking questions from an audience of pre-selected undecided voters during a so-called “town hall” event at New York's Hofstra University.

Analysts say Mr. Romney delivered the stronger performance in their first debate earlier this month.

But former White House spokesman Robert Gibbs told MSNBC Mr. Obama would be “strong,” “passionate” and “energetic” during this debate.

The latest USA Today/Gallop poll released Monday shows the former Massachusetts governor leading President Obama by four percentage points among likely voters in the nation's top 12 battleground states.

The survey found the Republican nominee has pulled within one point of Mr. Obama among women who are likely voters. He is leading the president by eight points among men likely to vote in those swing states.

Mr. Romney's campaign announced this week it raised $170 million in September.

Last week, the Obama campaign announced it raised $181 million last month.