President Joe Biden acknowledged again Tuesday that he didn’t have the “best debate night” during his match-up against his presumptive GOP competitor, Donald Trump, but said he is “feeling good about what’s happening” with his campaign.

The president made the remarks at a fundraiser in McLean, Virginia, amid growing concern among prominent Democrats about his reelection bid. The White House has been on damage control over the past week, attempting to assuage voters’ fears about Biden’s age.

He said Tuesday that his schedule before the debate “wasn’t very smart,” noting he had traveled around the world “a couple times” beforehand.

“I decided to travel around the world a couple times, going through I don’t know how many time zones,” Biden said. “For real I think it was 15 time zones…I didn’t listen to my staff.”

“And then I almost fell asleep onstage,” he added.

The president went on to apologize to donors for his performance, but said it was “critical” Democrats win the election, and said his remarks were “not an excuse, but an explanation.” He said his reelection bid had raised $38 million since his debate appearance. 

Biden did have two international trips in the weeks before the debate, including a visit to France and then another to the G7 summit in Italy.

It remains unclear how his effort will play with the party as it heads into its nominating convention in August. Many of Biden’s allies — including former President Barack Obama and California Gov. Gavin Newsom (D) — have come to his defense, while others have begun to break away. Democratic Rep. Lloyd Doggett (Texas) called on Biden to give up his bid, the first party member in Congress to do so.

Former House Speaker Nancy Pelosi (D-Calif.) also said it was understandable to ask about the president’s fitness.