A federal appeals court has upheld a U.S. law requiring TikTok‘s Chinese parent company to sell the wildly popular app by January 19 or face a ban.

TikTok and its supporters argued that the law violated their First Amendment free speech protections, but the three-judge panel didn’t agree, holding that the the government “acted solely to protect” Americans “from a foreign adversary nation.” The fight could now head to the U.S. Supreme Court. More than 170 million Americans use TikTok, and just 32% of U.S. adults support a ban, according to a recent Pew survey.

We’ll be following this story closely; read more here.