Unless the Supreme Court temporarily blocks a federal law requiring TikTok be sold to a non-Chinese entity or else be prohibited in the U.S., a ban on the app will go into effect on Jan. 19 that could affect millions of users and is likely to upend content creators’ livelihoods.

Indications during oral arguments on Friday suggested that the court is inclined to uphold the lawwhich President Joe Biden signed in April. If the ban is in effect on Jan. 19, the popular social media platform may be removed from app stores, but it probably won’t disappear from users’ phones immediately. User experience could deteriorate over time, as security patches and updates won’t be available to download, CNN reported.

However, if the court decides not to block the law or to delay the Jan. 19 deadline, the app’s fate may lie with President-elect Donald Trump, who will be inaugurated on Jan. 20.

Trump has said he opposes the ban and that he would “save” TikTok. Last month, he asked the Supreme Court to pause the law so that he can “pursue a political resolution” after he takes office. If the court acquiesces, Trump could grant a 90-day extension to TikTok’s parent company, ByteDance, to continue seeking a buyer.

But ByteDance has long insisted that it is not interested in selling TikTok, and the Chinese government has indicated that it would block any sale that includes the app’s valuable algorithm. There has been at least one U.S.-based offer to buy TikTok without its algorithm, from “Shark Tank” star Kevin O’Leary and billionaire entrepreneur Frank McCourt. TikTok did not respond to CNBC’s request for comment.

As president, Trump could also take the more difficult route of trying to reverse the law. He might try to pressure Congress to repeal the legislation, which seems unlikely to succeed, considering it passed with strong bipartisan support. Such a move would also be a major test of his influence over his party, which currently has slim majorities in both chambers of Congress.

Otherwise, Trump could direct his Justice Department simply not to enforce the ban and decline to penalize companies that continue to make the app available on their app stores. However, ABC News has reported that some experts are skeptical that companies would be willing to open themselves up to such a risk.

In any event, TikTok’s future in the U.S. hangs in the balance for now. The Supreme Court is expected to issue a preliminary decision prior to the deadline.

Clarissa-Jan Lim

Clarissa-Jan Lim is a breaking/trending news blogger for BLN Digital. She was previously a senior reporter and editor at BuzzFeed News.