Updated

President Barack Obama and Republican Mitt Romney are each forgoing time on the campaign trail Sunday in favor of hours of intense debate preparation ahead of their next face-to-face meeting.

Obama, seeking to rebound from a widely panned performance at the first debate, was huddling with advisers at a sprawling riverfront resort in Williamsburg, Va. Romney retreated to his Boston-area home, where the Republican nominee was working to replicate his commanding turn on the debate stage.

The days devoted to debate preparations underscore just how important the next face-off, which falls exactly three weeks from Election Day, is to both campaigns. Millions of Americans are already casting their ballots through early voting, meaning there are few opportunities to recover from slip-ups in what remains an exceedingly close race.

Following a listless first debate, Obama was working with aides on more pointed and aggressive responses to Romney. The campaign's game plan is also to target Romney for what it sees as a willingness to shift his positions to make them more palatable for voters.

"Governor Romney has been making pitches all of his life," Obama spokeswoman Jennifer Psaki said of the businessman-turned Republican nominee.

"He knows how to say what people want to hear whether that was during his time at Bain or during the dozens of town halls he did during the primary," she added, referring to the private equity fund Romney used to run.

While Romney prepped for the debate, his campaign released a new television advertisement using footage of Republican running mate Paul Ryan's debate this week with Vice President Joe Biden. The ad, titled "Fiscal Discipline", features clips of Ryan saying the government "can't keep spending money we don't have." His comments are juxtaposed with video from the debate of Biden laughing.

The campaign did not say in which states the ad would run.

Ryan and Biden were each cheered by their party's base after their debate. But the focus shifts back to Obama and Romney on Tuesday at Hofstra University in Hempstead, N.Y.

Obama aides have tried to make debate preparations a higher priority for the president this time around. Ahead of first debate, some of Obama's practice sessions were cut short, and others canceled all together, mainly because of developments in Libya, where four Americans were killed at a U.S. consulate.

Aides say Obama is still dealing with those matters and others. But the urgency that led to interruptions during earlier debate prep has subsided, and the campaign is trying to ensure that Obama stays more fully engaged in his practice sessions.

Despite questions about the effectiveness of his debate preparation, Obama is working with the same team this time around. Senior advisers David Axelrod and David Plouffe, along with former White House officials Anita Dunn and Ron Klain, are still running the preparations. Deputy national security adviser Ben Rhodes has also been added to the team because the second and third debates involve foreign policy.

Sen. John Kerry, D-Mass., is playing the role of Romney.

Among the campaign's chief priorities during the practice sessions is sharpening the president's retorts to Romney and drawing a sharper contrast between what the campaign says are Romney's shifting positions on key issues.

The president may have picked up a few pointers from Biden.

Obama watched that debate with aides in a conference room on Air Force One as he traveled back to Washington. The president said little throughout the debate, but did chime in when Biden would deliver a particularly pointed counter to Ryan.

"That's a good one," Obama said, according to aides.

Romney returned to Massachusetts Saturday night, planning to spend most of two days at his Belmont home getting ready for the upcoming debate.

With Romney is Ohio Sen. Rob Portman, who's playing President Barack Obama in mock debates. Playing moderator Candy Crowley is Peter Flaherty, a longtime Romney aide.

Romney typically attends church on Sunday mornings at the chapel of the Church of Jesus Christ of Latter-day Saints near his house. He planned to spend Sunday afternoon at a nearby hotel.

Romney spent most of the past week campaigning in Ohio, a state critical to his presidential hopes.