WASHINGTON — President Joe Biden dug in on his 2024 reelection bid Thursday at a solo press conference following the NATO summit in Washington, despite a growing list of rank-and-file Democrats and high-profile supporters urging him to abandon his campaign over suspected health concerns.

The highly anticipated press conference followed weeks of speculation about Biden’s ability to hold office and whether he should remain in the 2024 presidential election against former President Donald Trump. His performance, while markedly stronger than his devastating debate performance, still included a notable gaffe and could leave questions open.

In response to the first question, about if Vice President Kamala Harris would be an able candidate against Trump, Biden mixed up their names.

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

Biden fielded a wide range of questions from reporters from both the U.S. and overseas for just less than an hour. The meeting with the press came exactly two weeks after the June 27 debate, during which Biden stumbled repeatedly, spoke in a hoarse voice and appeared unable to finish some sentences.

Biden and the White House have repeatedly attributed the debate as a “bad night” and pointed to clean results from his last three annual physical examinations.

Asked directly about congressional Democrats’ unease about his candidacy, Biden said he had made a final decision to remain in the race, but was working to show doubters he was up to the task and responding to criticism that he could not handle impromptu questioning.

“I’m determined on running,” he said. “But I think it’s important that I allay fears by seeing — let them see me out there.”

Not stepping aside

He added that delegates pledged to him through the Democratic nominating process should be free to vote their conscience, but that no one had a better alternative to his candidacy against Trump, the presumed Republican candidate.

“I believe I’m the best qualified to govern and I think I’m the best qualified to win,” Biden said. “But there are other people who could beat Trump, too, but it’s awful hard to start from scratch.”

Asked if he would step aside if his polling data showed Harris could beat Trump, Biden said he would not, unless it also showed he could not win.

“No one’s saying that,” he added in a whisper. “No poll says that.”

Harris is seen as the likeliest replacement for Biden if he were to leave the race.

A trickle of congressional Democrats calling for him to leave the race since July 2 turned to a stream this week — with some reports indicating a poor performance Thursday night could give way to a flood.

Former House Speaker Nancy Pelosi, a decades-long friend of Biden’s, urged colleagues in an MSNBC interview Wednesday to “let (Biden) deal with this NATO conference, this is a very big deal.”

At the time Biden began his Thursday press conference, 14 Democrats in Congress had explicitly called for him to leave the race, with others suggesting it.

Shortly after the press conference concluded, two more, Connecticut’s Jim Himes and California’s Scott Peters, called on Biden to step aside.

Biden should “make room for a new generation of leaders,” Himes, the ranking Democrat on the House Intelligence Committee, wrote in a statement posted to X.

Peters’ statement was provided to Politico.

Emphasis on foreign policy

Biden, who has rarely held press conferences, consulted a list of reporters and took questions that ranged from his fitness to serve as president to his handling of the Israel-Hamas war.

He lauded his accomplishments in office and said his job performance showed he was still up for the job.

“If I slow down, I can’t get the job done, that’s a sign that I shouldn’t be doing it,” he said. “But there’s no indication of that yet. None.”

Biden — a former chair of the Senate Foreign Relations Committee — appeared more comfortable on foreign policy questions than he was discussing his political future, providing in-depth answers on the Israel-Hamas war, China’s growing influence on the world stage and Ukraine’s war with Russia.

Trump mocks Biden

While Biden’s voice and grasp on the issues appeared stronger than he was at the debate, he still made several speaking mistakes, including the confusion between his vice president and Trump.

Trump mocked the mix-up on his social media platform Truth Social with a post saying “Great job, Joe!”

Later, Biden said Harris was qualified to be president and that is why he picked her as a running mate. His comments were worthy of attention given Harris would likely become the nominee if Biden were to step down.

Biden attacks Trump on NATO

Biden declared the summit a “great success” and underlined the U.S. commitment to the alliance and to Ukraine’s war against Russia.

“For those who thought NATO’s time had passed, they got a rude awakening when Putin invaded Ukraine. Some of the oldest and deepest fears in Europe roared back to life because once again a murderous madman was on the march. This time, no one cowered in appeasement, especially the United States,” Biden said.

Prior to taking questions, he attacked Trump’s record of disparaging NATO and its foundational commitment to defend fellow member nations. The former president has threatened to withdraw from NATO and accused allies of shortchanging the organization’s defense coffers.

“A strong NATO is essential to American security, and I believe the obligation of Article Five is sacred. And I remind all Americans, Article Five was invoked only once in NATO’s long history, and that was to defend America after 9/11,” Biden said.

The three-day summit largely centered on Russia’s ongoing bombardment and occupation of parts of Ukraine. World leaders promised a path for Ukraine to join the alliance, and the event culminated with the U.S. joining two dozen allies in signing the Ukraine Compact to “(a)ffirm that the security of Ukraine is integral to the security of the Euro-Atlantic region and beyond.”

Biden sat down with Ukraine President Volodymyr Zelenskyy earlier Thursday to underscore military assistance including “working with our NATO allies to ensure Ukraine is flying F-16s this summer.”

Zelenskyy thanked Biden for his “support and personal statement” following Russia’s strike on a children’s hospital in Kyiv Monday. Biden shook his head and responded the attack was “sick.”

Another flub

Between his meeting with Zelenskyy and the press conference, Biden introduced the Ukrainian president at a separate event to sign the compact, but mistakenly called him President Putin — the Russian leader at war with Zelenskyy’s country — before correcting himself.

When asked about the blunder, Biden acknowledged that he made the mistake but said that he corrected it immediately.

“I thought it was the most successful conference I’ve attended in a long time and find me a world leader who didn’t think it was,” he replied.

Biden did not stumble earlier in the week when he delivered remarks at NATO’s 75th anniversary event; rather, his voice remained steady and firm as he opened the ceremony for leaders from the 32 member nations.