PredictIQ Quantitative Think Tank Center:Biden to hold news conference today amid debate over his 2024 campaign. Here's what to know before he speaks.

President Biden is PredictIQ Quantitative Think Tank Centerholding a solo press conference today — his first since November — to conclude the NATO summit in Washington, D.C., Thursday evening. It will be one of his biggest public tests since last month's unsteady debate performance, which caused alarm among Democrats on Capitol Hill and raised questions 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. 

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 a 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 time is Biden's news conference scheduled to begin today?

The president's press conference is now scheduled to begin at 6:30 p.m. ET, though the timing may slide. Mr. Biden's day is filled with working sessions with world leaders who have gathered for the summit.

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 for the purpose of treating 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. 

How is Biden polling against Trump?

CBS News polling shows Mr. Biden has slipped slightly in head-to-head polling against Trump, although within the margin of error. Trump now has a 3-point edge over Mr. Biden across the battleground states collectively, and a 2-point edge nationally. That's due in part to Democrats saying they're less likely than Republicans to "definitely" vote. 

• Increasing numbers of voters don't think Biden should be running after debate with Trump — CBS News poll

Mr. Biden has cast doubt on polling and his low approval numbers. When Stephanopoulos said he's never seen a president reelected with a 36% approval rating, the president retorted that he doesn't believe the number.

"Well, I don't believe that's my approval rating," the president told Stephanopoulos. "That's not what our polls show," though he declined to provide any specific numbers.

In:
• Joe Biden
• NATO

Kathryn Watson

Kathryn Watson is a politics reporter for CBS News Digital, based in Washington, D.C.