Biden Mixes Up Kamala Harris and Donald Trump at News Conference

President Biden referred to Vice President Kamala Harris as “Vice President Trump,” flubbing his response to the first question posed to him in a much-awaited news conference during a summit of NATO leaders.

Mr. Biden was asked by a Reuters reporter if he had concerns about Ms. Harris’s ability to beat former President Donald J. Trump if he stepped aside, something he has said emphatically that he will not do despite pressure from many within his party.

“Look, I wouldn’t have picked Vice President Trump to be vice president if I didn’t think she was qualified to be president,” he said.

Mr. Biden had another gaffe earlier in the evening, introducing President Volodymyr Zelensky of Ukraine as “President Putin” after a meeting of NATO leaders in Washington.

“I want to hand it over to the president of Ukraine, who has as much courage as he does determination,” Mr. Biden said from the lectern with Mr. Zelensky at his side. “Ladies and gentlemen: President Putin.”

Mr. Biden stepped away from the lectern before realizing his mistake.

“President Putin?” Mr. Biden said as he returned to the microphone. “We’re going to beat President Putin. President Zelensky. I’m so focused on beating Putin. We got to worry about it. Anyway.”

Mr. Biden turned to shake Mr. Zelensky’s hand. The Ukrainian president joked, “I’m better,” to which Mr. Biden replied, “You are a hell of a lot better.”

The gaffes could not have been more ill-timed for the Biden campaign, coming as the president battles a crisis of confidence among Democrats considering if he is the best candidate to beat Mr. Trump in November. The news conference where Mr. Biden mixed up Mr. Trump and Ms. Harris was much anticipated by Democratic defenders and skeptics of the president’s