The decision comes as many young and left-leaning voters, a significant part of the user base for the short-video app, are agitated over Biden's handling of the war in Gaza and protests have escalated across universities around the country.

"A fragmented media environment requires us to show up and meet voters where they are -- and that includes online. TikTok is one of many places we're making sure our content is being seen by voters," said a Biden campaign official, who declined to be named.

The campaign will use "enhanced security measures" while using the app, the official said. Biden's campaign staff are not employed by the government and do not deal with national security issues, so they are allowed to have the app on their phones, campaign officials had previously said.

The Biden campaign account on TikTok, @bidenhq, has posted close to 120 videos and has more than 306,000 followers, and routinely posts videos of Biden there, even as the White House says TikTok causes "legitimate national security concerns."

TikTok is set to challenge the bill on First Amendment grounds and the company's chief executive said on Wednesday he expects to win a legal challenge to block the legislation.

The four-year fight over TikTok is a major front in a battle over the internet and technology between Washington and Beijing.

Republican presidential candidate Donald Trump, who is not on the app, said earlier this week Biden was responsible if a ban were imposed, urging voters to take notice. When he was president in 2020, Trump tried to ban TikTok over national security concerns but was blocked by the courts.

Biden campaign aides do not expect the decision to hurt them with young voters and expect a lengthy legal fight to determine the app's fate and to delay any potential ban.

"Reducing young people's vote down to the use of a social media app is unserious, inaccurate and insulting: election after election, young people continue to show us they understand the stakes of this moment," said Biden campaign spokesman Seth Schuster.

In March, the campaign said it has launched its largest voter outreach program, with the support of 15 youth organizations who have endorsed Biden.

The new law gives TikTok's Beijing-based parent company, ByteDance, nine months to sell the app or face a ban in the U.S. The president could grant a one-time 90-day extension, but even without it, the earliest a ban could start is January.