Biden the president wants to curb TikTok. Biden the candidate embraces his stars.

The White House is so concerned about TikTok’s security risks that federal employees are not allowed to use the app on their government phones. Top Biden administration officials have even helped draft legislation that could ban TikTok in the United States.

But those concerns were put aside Thursday, on the evening of President Biden’s State of the Union address, when dozens of social media influencers — including many TikTok stars — were invited to the White House for a watch party.

The crowd took selfies in the State Dining Room, drank bubbly with the first lady and waved to Mr. Biden from the White House balcony as he left to deliver his speech to Congress.

“Don’t jump, I need you!” Mr Biden shouted at the young influencers filming from above, in a scene that was – of course – captured in a TikTok video, which was broadcast to hundreds of thousands of people.

Thursday’s party at the White House was an example of Mr. Biden’s political concerns colliding head-on with his national security concerns. Despite growing fears that ByteDance, TikTok’s Chinese parent company, could breach Americans’ personal data or manipulate what they see, the president’s campaign is banking on the app to energize a frustrated bloc of young voters. in the run-up to the 2024 elections.

“From a national security perspective, the campaign joining TikTok definitely didn’t look good — it condoned the use of a platform that the administration and everyone in DC recognizes is a national problem,” said Lindsay Gorman, chief technology and geopolitics officer at the German Marshall Fund and a former technical advisor to the Biden administration.

TikTok is the most popular platform among American teenagers after YouTube, making it an attractive political tool. But concerns about the app’s structure have grown, and a House committee this week introduced a bill that would keep TikTok out of U.S. app stores unless the platform broke away from ByteDance.

When members of Congress talk about TikTok, they tend to focus on its privacy issues, and whether data about users is stored in China or accessible to Chinese officials who can demand the company turn over the information.

But national security officials have a deeper concern: The algorithms that determine what users see are now designed almost entirely in China. The key is to prevent Chinese engineers, perhaps under state influence, from using the code in ways that could censor or manipulate what American users see. TikTok has pushed back on such concerns, saying its opponents have not provided evidence to support these fears.

That’s especially important, officials say, as election season approaches. If Chinese officials wanted to influence the election, the app could provide a subtle way to do so. But even the legislation now being passed by Congress may not have an impact on that: it would not come into effect until five months after a law is signed. At most, that would be a month or so before Election Day.

The White House has supported the restrictions.

Mr. Biden’s National Security Council called the bill in the House of Representatives “an important and welcome step” and White House press secretary Karine Jean-Pierre said it should be quickly sent to the president’s desk for his signature. While the legislation’s path in the Senate is unclear, Mr. Biden claimed on Friday that he had approved the package.

“If they approve it, I will sign it,” Mr. Biden said.

ByteDance has spent Mr. Biden’s term promoting a plan to address security concerns surrounding TikTok by storing its U.S. user data on Oracle servers in the United States. That plan formed the core of a 2022 draft agreement between ByteDance and government negotiators. But senior government officials at the time were concerned that the proposed deal did not go far enough to address their concerns.

Despite all those concerns, TikTok’s political benefits were clear this week.

Harry Sisson, a 21-year-old political commentator on TikTok, reached more than 800,000 followers from his perch in the White House as he and others watched Mr. Biden’s State of the Union address on Thursday.

“He called the Supreme Court directly to their faces for overturning Roe v. Wade,” Mr. Sisson said in a message during the speech. “You have to see this, watch the clip.”

Later, in his fourth video during the speech, Mr. Sisson said of the president, “He came to talk to us about how content creation is super important in 2024 because, you know, the media landscape is changing.”

He added: “No one really watches cable news anymore.”

The Biden campaign declined to answer questions about the specific security protocols for posting TikToks or why the campaign embraced the platform before spinning it out of ByteDance. The White House has denied that Mr. Biden’s national security team wants to ban the app.

“We don’t see this as a ban on these apps – that’s not what this is – but by ensuring that their property does not end up in the hands of those who could harm us,” Ms Jean-Pierre said on Wednesday. “This is obviously about our national security, and this is what we are focused on here.”

The Biden campaign joined TikTok on the night of the Super Bowl.

Previously, the government had avoided opening its own TikTok accounts while tapping into the app’s audience by inviting social media stars to briefings on the Covid-19 vaccines and Russia’s invasion of Ukraine. But after rejecting the traditional presidential halftime interview on Super Bowl Sunday, the campaign arrived on TikTok with an inaugural post mocking a right-wing conspiracy theory claiming Biden rigged the game.

Democrats say the embrace of social media platforms like TikTok is an effort to meet voters where they are.

“We have to deal with the cards we’ve been dealt,” said Quentin James, co-founder of Collective PAC, an organization that aims to elect Black officials. “If the tools are available, we should use them, even if there are international security problems. If the Biden campaign were to lose access to this and leave it to the Trump campaign and others to use it, that would be an extreme disadvantage.”

Former President Donald J. Trump attacked the administration for the possible ban on TikTok, saying it would only give Meta, Facebook’s parent company, more power.

Mr. Trump’s criticism of this effort was notable because he had worked to sell TikTok’s U.S. operations to Oracle during his time in office. Its CEO, Safra Catz, was a member of Trump’s 2016 transition team and a major supporter of the campaign.

As the campaign tries to use the platform to connect with younger voters, efforts by the White House and Congress to reform the company have enraged TikTok users. After the bill was introduced this week, TikTok took the unusually aggressive step of sending a pop-up message to US users on Thursday asking them to call their representatives and protest the bill. Some Capitol Hill offices said they were inundated with calls, including from teenagers. Lawmakers complained that TikTok misrepresented the bill by claiming it required an immediate ban on the platform.

Meanwhile, a video the Biden campaign posted about the North Carolina governor’s race quickly gathered responses asking Mr. Biden to halt a TikTok ban.

One user expressed his confusion in a comment that drew likes from others on the app: “Aren’t you about to ban TikTok? Why did your team make you an account in the first place?

David McCabe And David E. Sanger contributed reporting from Washington.