The Supreme Court seemed inclined on Friday to uphold a law that would force a sale or ban the popular short-video app TikTok in the United States by Jan. 19, with the justices focusing on the national security concerns about China that prompted the crackdown.

The law that could ban TikTok is coming before the Supreme Court. The justices largely hold the app’s fate in their hands as they hear the case Friday.

The court is hearing oral arguments on TikTok’s bid to block a law that would lead to its ban in the U.S. starting Jan. 19 if it isn’t sold by its Chinese owner.