A federal appeals court upheld a law on Friday mandating that ByteDance, the Chinese parent company of the social media platform TikTok, divest its operations in the United States by Jan. 19 or face a nationwide ban of the app.

The 92-page ruling, delivered by Judges Sri Srinivasan, Neomi Rao, and Douglas Ginsburg, marks a significant step in efforts to address national security concerns tied to TikTok’s Chinese ownership. The law, however, can be challenged in the Supreme Court or before the full appeals court panel.