TikTok’s future in the U.S. appeared uncertain on Friday after a federal appeals court rejected a legal challenge the company brought against a law that requires it to cut ties with its China-based parent company or be banned by mid-January.

A federal appeals court panel on Friday unanimously upheld a law that could lead to a ban on TikTok as soon as next month, handing a resounding defeat to the popular social media platform as it fights for its survival in the U.S. The U.S. Court of Appeals for the District of Columbia Circuit ruled that the law - which requires TikTok to break ties with its China-based parent company ByteDance or be banned by mid-January — is constitutional, rebuffing TikTok’s challenge that the statute ran...