WASHINGTON TikTok's chief executive said on Wednesday that the company expects to win a legal challenge to block legislation signed into law by President Joe Biden that he said would ban the popular short video app used by 170 million Americans.

"Rest assured - we aren't going anywhere," CEO Shou Zi Chew said in a video posted moments after Biden signed the bill that gives China-based ByteDance 270 days to divest Tiktok's US assets or face a ban. "The facts and the Constitution are on our side and we expect to prevail again."

In 2020, then-president Donald Trump was blocked by the courts in his bid to ban TikTok and Chinese-owned WeChat, a unit of Tencent, in the US.

Chew added: "Make no mistake - this is a ban on TikTok." He emphasised that TikTok would continue to operate as the company challenges the restrictions.

Driven by widespread worries among US lawmakers that China could access Americans' data or surveil them with the app, the bill was passed late on Tuesday by the US Senate. The US House of Representatives approved it on Saturday.

The four-year battle over TikTok is a significant front in a war over the internet and technology between Washington and Beijing. Last week, Apple said China had ordered it to remove Meta Platforms' WhatsApp and Threads from its App Store in China over Chinese national security concerns.

TikTok is set to challenge the bill on First Amendment grounds and TikTok users are also expected to again take legal action. A US judge in Montana in November blocked a state ban on TikTok, citing free-speech grounds.

The American Civil Liberties Union said banning or requiring divestiture of TikTok would "set an alarming global precedent for excessive government control over social media platforms."

However, the new legislation is likely to give the Biden administration a stronger legal footing to ban TikTok if ByteDance fails to divest the app, experts say.

If ByteDance failed to divest TikTok, app stores operated by Apple, Alphabet's Google and others could not legally offer TikTok or provide Web hosting services to ByteDance-controlled applications or TikTok's website.

  - Reuters