President Biden held a solo press conference on Thursday— his first since November — to conclude the NATO summit in Washington, D.C., Thursday evening.  A number of questions he's received are about whether he should remain at the top of the Democratic ticket.

The news conference represents one of his biggest public tests since last month's unsteady debate performance, which caused alarm among Democrats on Capitol Hill and raised concerns about whether he should be the party's 2024 presidential nominee.

The president has acknowledged he had what he says was a "bad night" at the debate and he has been trying to prove he can be the nominee and defeat former President Donald Trump. But the president didn't help his case when, shortly before the press conference, he introduced Ukrainian President Volodymyr Zelenskyy as "President Putin," to the shock of other world leaders. 

The president soon realized his error and corrected himself, retaking the podium. "I'm so focused on beating Putin," Mr. Biden explained. 

The president began the press conference by touting the successes and history of NATO.

"For those who thought NATO's time had passed, they got a rude awakening when Putin invaded Ukraine," he said. 

And the president sought to contrast himself with Trump. 

"Meanwhile, my predecessor has made it clear he has no commitment to NATO," Mr. Biden said. 

What questions did Biden answer during his news conference?

As he began to take questions, the president stumbled almost immediately. 

Mr. Biden was asked what concerns he has about the ability of Vice President Kamala to beat Donald Trump if she were at the top of the ticket. 

"Look, I wouldn't have picked Vice President Trump to be vice president if I didn't think she was qualified to be vice president," he responded. 

Asked about Harris' qualifications later, Mr. Biden said she is "qualified to be president — that's why I picked her." 

"First of all, the way she's handled the issue of freedom of women's bodies, to have control over their bodies," he said. "Secondly, her ability to handle over any issue on the board, this is a hell of a prosecutor."

Biden says running is not about his legacy

CBS News chief White House correspondent Nancy Cordes asked the president if he's spent time thinking what it would mean for his legacy if he were to stay in the race and then lose to Trump. 

"Well look, I'm not in this for my legacy," the president replied. "I'm in this to complete the job I started."

The president pointed to the strength of the economy, and how inflation has stabilized. 

Biden says he should "pace myself a little more" The president was asked about reporting that he told Democratic governors he wants to limit events past 8 p.m., and needs more time to sleep. He insisted that wasn't the case. 

"Look, what I said was instead of my every day starting at 7 a.m. and going to bed at midnight, it would be smarter for me to pace myself a little more," he said. "And I said for example, the 8, 7, 6 — instead of starting a fundraiser at 9:00, start it at 8:00. People get to go home by 10:00. That's what I'm talking about."

"And if you look at my schedule since I've — since I made that stupid mistake of — in the campaign — in the debate, I mean, my schedule has been full bore," he added. 

Biden once saw himself as "bridge" to new generation. What changed? 

In 2020, one reporter pointed out, Mr. Biden referred to himself as a "bridge" candidate to a younger, newer generation of Democratic leaders. What changed, she asked him. He touted his accomplishments "more than most any president since Johnson," and his "wisdom on how to deal with the Congress to get things done." He indicated that he felt he wasn't done. "I want to finish, to get that finished," he said.

Referring to the threat he says that Donald Trump and the conservative-majority Supreme Court pose to democracy, Mr. Biden said, "We have never been here before. That is why I didn't hand off to another generation —I have to finish this job because there's so much at stake."

Biden points to the success of the NATO summit 

The president made the case for his candidacy by arguing that people should look at the product of his work. He asked a reporter to name a more successful NATO summit than this one. 

"The idea anybody suggests that we haven't had an incredibly successful conference, how many times did you hear, in that conference — I know it sounds too self serving — but other leaders, heads of state, in thanking me, and saying the reason we're together is because of Biden?" he said. 

Mr. Biden has consistently urged Europe and countries outside of Europe to unite and stand for Ukraine. 

What spurred this concern about Biden's campaign?

During the debate, Mr. Biden, 81, stumbled early on, flubbing lines as his voice appeared ready to give out. His campaign later said he was suffering from a cold. His voice never recovered throughout the 90-minute debate, he failed to effectively respond to a number of false statements made by Trump during the debate, and at times he lost his train of thought. At one point, he struggled to name Medicare when answering a question about the tax rate for wealthy Americans, and then said that "we finally beat Medicare." 

Mr. Biden's campaign had hoped to allay concerns about his age with the early debate, but instead, that performance is now threatening his political future.

Recently, Mr. Biden said the NATO summit could be a test of his fitness for office, and Democrats on Capitol Hill, Democratic governors, and world leaders will be watching, too. 

"Who's going to be able to hold NATO together like me," the president challenged ABC's George Stephanopoulos in an interview last week. He added, "I guess a good way to judge me is you're going to have now the NATO conference here in the United States next week. Come listen. See what they say."

Democratic Sen. Chris Van Hollen of Maryland told the Washington Post the NATO summit "gives [Mr. Biden] an opportunity to showcase his leadership and foreign policy credentials and the press conference gives him an opportunity to address concerns."

The president has declined to agree to take an in-depth neurocognitive test, telling Stephanopoulos on Friday that every day in office is a cognitive test.

"I'm running the world," the president said. 

Aside from the ABC News interview, the president has largely relied on teleprompters to deliver speeches. Some Democrats say they want to see the president unscripted on the campaign trail and to meet with him in person, while reporters have called on the president to hold a press conference as soon as possible. 

What's happened at NATO?

Russia's war on Ukraine continues to be a key theme for NATO, as Mr. Biden and other world leaders make the case that Russia will not stop at Ukraine. The president announced air defense equipment will be given to Ukraine by the U.S., Germany, the Netherlands, Romania, and Italy. In the coming months, the U.S. and its partners will provide Ukraine with dozens of additional tactical air defense systems, he said. 

"We know Putin won't stop at Ukraine. But make no mistake — Ukraine can and will stop Putin," the president said of Russian President Vladimir Putin.

Latest information about the president's health

White House press secretary Karine Jean-Pierre said this week that the president has not been diagnosed with Parkinson's disease or any other serious neurological disorder. 

On Tuesday, Jean-Pierre said Walter Reed neurologist Dr. Kevin Cannard's January visit to the White House was not to treat the president. But on Tuesday night, the Associated Press reported that Cannard visited Mr. Biden at the White House in January. Jean-Pierre then released a statement saying that Cannard had in fact met with the president at the White House in January, but only as a part of his annual physical, the rest of which was completed in February.

The White House and the president say he's up for another four years on the job, despite concerns from voters and some Democrats.