(CNN) — President Joe Biden told Democratic governors during a meeting at the White House on Wednesday that part of his plan going forward is to stop scheduling events after 8 p.m. so that he can get more sleep, according to three sources briefed on his comments.

The remarks, first reported by The New York Times, came as the 81-year-old Biden sought to reassure a group of more than 20 state leaders about his ability to defeat former President Donald Trump in November and govern effectively for another four years.

Biden’s comment left several of the governors in the room frustrated, sources told CNN, and is one of the reasons that some of the participants have been rankled by the statement of loyalty and enthusiasm from them distributed by the Biden campaign on Thursday.

The White House did not immediately comment about what the president said. A Biden campaign aide argued that, as well as doing debate prep in the week after his two trips to Europe, Biden was engaged in hours of official work in addition to the hours of campaign work.

“President (George W.) Bush went to bed at 9, and President (Barack) Obama made dinner at 6:30,” said Biden campaign spokesperson Kevin Munoz. “Normal presidents strike a balance, and so does Joe Biden. Hardly the same rigor as Donald Trump, who spends half of his day ranting on Truth Social about plans that would cause a recession and the other half golfing.”

Biden also made a joke to the governors that didn’t go over well: “I’m fine — I don’t know about my brain, though.” Jen O’Malley Dillon, Biden’s campaign chairwoman, said the president was “clearly making a joke and then said, ‘All kidding aside.’”

In the wake of Biden’s poor performance during CNN’s presidential debate last week, some Democrats have begun to call for the president to drop out of the race, leaving the White House scrambling to convince skeptics within the party and voters. In the days after, administration officials have provided confusing and conflicting explanations as they attempted to spin a performance that exacerbated voters’ concerns about Biden’s age.

Following the meeting, Govs. Wes Moore of Maryland, Kathy Hochul of New York and Tim Walz of Minnesota painted a positive picture of the meeting during a news conference, adding that Biden is “all in” and “in it to win it.”

In response to a reporter’s question, Walz dismissed any concerns about Biden’s age and health, saying the president is “fit for office.”

Campaigning for Biden in South Haven, Michigan, on Thursday, California Gov. Gavin Newsom — who attended the meeting in person — told CNN that Biden’s acknowledging his fatigue shows he’s “human” and said he felt people were making too much of the remark.

“Look at his schedule, look at the fundraising things that you don’t see. All that work, the work you’re doing behind the scenes, the phone calls you’re making times all times of night. Alliance management, everything he’s doing to prepare for NATO this week, what they’re doing to land a deal with Hamas and Israel,” Newsom said.

Biden, the oldest president in US history, has faced questions around his age and health for years. They came to a head during the debate, when he was hoarse and at times unintelligible, leaving Trump — who is only three years younger than Biden — to appear more fit. The majority of debate watchers deemed the former president as the winner of the stand-off, according to a CNN poll.

And Biden’s debate performance opened the floodgates for more scrutiny and reporting on the president’s health, with sources describing a decline in his mental fitness.

The New York Times reported earlier this week that the president’s “lapses” have increased and grown more worrisome, with a source telling the Times that Biden’s six-day debate preparations at Camp David didn’t start before 11 a.m. and that the president was given time to nap each day.

White House press secretary Karine Jean-Pierre sidestepped a question during Wednesday’s briefing about whether the president takes daily afternoon naps following the Times’ reporting. But she offered jet lag and travel fatigue as an explanation for Biden’s poor debate performance after previously chalking it up to a cold.

Amid increasing pressure to consider dropping out of the race and growing concern whether he can serve another term, CNN has previously reported that Biden has privately expressed that the next stretch of days will be critical for whether he can save his reelection bid.

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