The US House of Representatives has overwhelmingly passed a bill that would give TikTok's Chinese owner ByteDance about six months to divest the American assets of the short-video app, or face a ban.
It is the greatest threat to the app since the Trump administration.
The bill passed by 352 votes to 65, with bipartisan support, but it faces a more uncertain path in the Senate where some favour a different approach to regulating foreign-owned apps posing security concerns.
Senate Majority Leader Chuck Schumer said members would review the legislation.
The fate of TikTok, used by about 170 million Americans, has become a major issue in Washington.
Politicians said their offices had received large volumes of calls from teenage users who oppose the legislation, with the volume of complaints at times exceeding the number of contacts seeking a ceasefire in Gaza.
"This process was secret and the bill was jammed through for one reason: it's a ban," a TikTok spokesperson said after the vote, adding that they hoped the Senate would "consider the facts, listen to their constituents," when looking at the bill.
The measure is the latest in a series of moves in the US to respond to security concerns about China, from connected vehicles to advanced artificial intelligence chips to cranes at American ports.
"This is a critical national security issue. The Senate must take this up and pass it," No. 2 House Republican Steve Scalise said on social media.
Senate Commerce Committee Chair Maria Cantwell, who will play an important role in the Senate's next move, said she wants legislation "that could hold up in court," and is considering a separate bill, but is not sure what her next step is.
Speaking in Washington, Taoiseach Leo Varadkar said Ireland and the EU have no plans to ban TikTok.
"What the United States decides to do in relation to TikTok or any other platform is a matter for themselves.
"We're not proposing that there'll be a ban in Ireland or the European Union. We have some concerns around security, we've put in place advisory protocols around that. But there's no proposals to have a ban in the European Union or Ireland," he said.
In Washington DC, Taoiseach says Ireland and EU have no plans to ban Tik Tok - even if US does. pic.twitter.com/tLOmxMeRTQ
— seanwhelanRTE (@seanwhelanRTE) March 13, 2024
The vote comes just over a week since the bill was proposed following one public hearing with little debate, and after action in Congress had stalled for more than a year.
Last month, President Joe Biden's re-election campaign joined TikTok, raising hopes among app officials that legislation was unlikely this year.
The House Energy and Commerce Committee last week voted 50-0 in favour of the bill, setting it up for a vote before the full House of Representatives.
TikTok Chief Executive Shou Zi Chew is visiting Capitol Hill today on a previously scheduled trip to talk to senators, amid popular support for the app.
Several dozen of its users rallied outside the Capitol building before the vote.
The company paid for their travel to Washington and accommodations, a TikTok spokesperson said.
But the political climate is in favour of the bill.
President Biden said last week that he would sign it and White House National Security Adviser Jake Sullivan said the goal was ending Chinese ownership, not banning TikTok.
"Do we want TikTok, as a platform, to be owned by an American company or owned by China? Do we want the data from TikTok - children's data, adults’ data - to be going, to be staying here in America or going to China?" he said.
It is unclear whether China would approve any sale or if the US assets could be divested in six months.
If ByteDance fails to do so, app stores operated by Apple, Google and others could not legally offer TikTok or provide web hosting services to ByteDance-controlled applications.
In 2020, then-president Donald Trump sought to ban TikTok and Chinese-owned WeChat but was blocked by the courts. In recent days he has raised concerns about doing so.
It remains unclear if WeChat or other high-profile Chinese-owned apps could face a ban under the legislation.
Any forced TikTok divestment from the US would almost certainly face legal challenges, which the company would need to file within 165 days of the bill being signed by the president.
There are still potential legal issues with the American Civil Liberties Union and other advocacy groups arguing the legislation is unconstitutional on free speech and other grounds.
In November, a US judge blocked a Montana state ban on TikTok use after the company sued.
