President Obama hunkered down at a golf resort here for the weekend to prepare for the next debate, which his own campaign acknowledges is critically important to stopping the momentum of Republican Mitt Romney.

Obama continued a tradition begun in Nevada by making an unscheduled trip Sunday afternoon to a local campaign office, where he delivered pizzas and rallied his field workers and volunteers. The president made a similar stop in Henderson, Nev., two weeks ago, when he sequestered himself for three days of preparations before the first debate in Denver.

The preparations in Williamsburg have taken on an urgency in the aftermath of Obama’s seemingly lethargic performance in that debate, which was widely panned and prompted a surge for Romney in numerous national and swing-state polls. Although Obama had previously been ahead in most polls and the candidates remain neck and neck in most battlegrounds now, Obama and his advisers acknowledge that he must deliver a strong performance Tuesday at Hofstra University to regain momentum.

“I think he is going to make some adjustments on Tuesday,” campaign adviser David Axelrod said on “Fox News Sunday,” adding that Obama will “be aggressive in making the case for his view of where we should go as a country.”

And on CNN’s “State of the Union” on Sunday, campaign adviser Robert Gibbs said: “Obviously, the president was disappointed in his own performance. He didn’t meet his expectations.”

Obama arrived at Kingsmill Resort on Saturday morning, and he will remain until Tuesday before flying to Long Island to appear in the second of three televised debates with Romney. Obama is spending time each day preparing with his team, both studying and practicing, according to the campaign. He was “excited” to get out of Washington, according to one campaign adviser speaking on condition of anonymity.

“This is a beautiful, quiet facility where he can still handle his governing responsibilities outside of the distractions of being at home,” the official said, adding that the president is “calm, focused and energized” and is spending time walking outside as well as preparing for the debate.

The team is largely the same as the one that helped him in Nevada: Axelrod, senior White House adviser David Plouffe, longtime adviser Anita Dunn, Sen. John Kerry (Mass.) and Washington lawyer and longtime Democratic debate coach Bob Barnett. National security adviser Ben Rhodes is helping with preparations because of the expected foreign-policy component at Tuesday’s town-hall-style debate. Kerry is playing the role of Romney and Dunn is playing CNN’s Candy Crowley, the debate’s moderator.

“The President is his own harshest critic and he knows Mitt Romney had a better night at the first debate,” campaign spokeswoman Jennifer Psaki said Sunday. “The American people should expect to see a much more energized President Obama making a passionate case for why he is a better choice for the middle class.”

That foreign-policy component is likely to focus on the recent events in Benghazi, Libya, where four Americans including U.S. Ambassador J. Christopher Stevens were killed during a siege on Sept. 11. The administration is under renewed scrutiny amid questions of whether the U.S. consulate there was adequately protected and what the administration has known and said publicly about the origins of the attacks.

Vice President Biden, in his own debate Thursday with Rep. Paul Ryan, raised more questions by blaming intelligence reports for the administration’s belief that the attacks were the result of protests rather than the work of terrorists — an apparent contradiction of the State Department’s statement earlier in the week that officials there had received no reports of protests outside the U.S. compound in Benghazi before the attacks.

Romney has jumped on the story, and is sure to try to do so again Tuesday at Hofstra.

“There were more questions that came out last night because the vice president directly contradicted the testimony of State Department officials,” Romney told supporters Friday at a campaign event in Richmond. “American citizens have a right to know just what’s going on.”

Obama’s debate preparations are taking place in the main building at Kingsmill, a sprawling golf resort along the James River featuring guest rooms and suites in free-standing villas that dot the golf course. Kerry was spotted early Sunday with a massive binder filled with color-coded spacers, and Axlerod was seen talking on his cell phone on the grounds.

Several other events are underway at the resort, including a medical conference and an event dubbed “Ferraris on the James.” Early Saturday, 11 Ferraris were spotted on the resort grounds, with their owners standing near their cars and valet attendants peering underneath.

During his stop at the campaign office, Obama was asked by the reporters following him how debate preparations are going, and he replied: “It’s going great!”

But the visit was more for the volunteers and field staff, whom he greeted with four boxes of pizza and a hearty “Hello everybody, hello!” on entering the office.

After greeting workers in the reception area, Obama went into a smaller room where 11 workers were making calls. He lowered his voice.

“Hello, everybody,” he whispered. “If you’re not on the phone, take a break.” He kissed the women and shook hands with the men.

One man said he was from London. Obama offered: “London! I like that.”

Then he sat between two women and picked up the phone to make some calls. “I’m gonna do my work. Everybody’s so serious!” On a call, he said: “Is this Ellen? Ellen, this is Barack Obama! It is really, truly me.”