It is unclear if Mr. Trump, who has previously said he will spare the social media platform, will or can stop the ban.

The popular social video platform faces a ban Jan. 19, unless the Supreme Court overturns the law booting it from the United States. Trump wants to put a thumb on the scales because he says it helped him get votes.

Incoming National Security Adviser Mike Waltz says the law allows a 90-day grace period for the app's Chinese owner.