The clock is ticking on TikTok.

The U.S. Supreme Court cited “well-supported national security concerns” and ruled Friday morning to uphold the congressional ban on the app on Sunday.

“The app will be banned on Sunday,” said Christopher Terry, associate professor of Media Law at the University of Minnesota Hubbard School of Journalism.

The U.S. Supreme Court upheld a law that is set to ban the social media platform unless it breaks ties with China-based parent company, ByteDance.

“The Supreme Court decision was sort of the last hope for stopping the implementation of the ban,” Terry said. “Unless something happens in the next 24-36 hours, I absolutely believe it’ll be dark.”

The Biden administration says it’s leaving the implementation of the law to President-elect Donald Trump, who will be sworn in on Monday. Trump says he expected this decision from the Supreme Court but said on Truth Social, “My decision on TikTok will be made in the not too distant future, but I must have time to review the situation. Stay tuned!”

On Friday, TikTok’s CEO addressed his millions of users in the U.S. while also responding to that Supreme Court decision.

“I want to thank President Trump for his commitment to work with us to find a solution that keeps TikTok available in the United States,” said Shou Zi Chew, Tik Tok’s CEO. “Rest assured, we will do everything in our power to ensure our platform thrives.”

“If they want the law to go away or the ban to go away, it would take an act of Congress signed into law by the president,” Terry said. 

Terry says it could take an executive order to suspend the implementation of the law. But he believes if nothing is done by Sunday, Apple and Google won’t keep the app running in the meantime.

“The financial penalties for doing so are very significant,” Terry said.

While TikTok users wait anxiously for what’s next, Terry believes this case could have major implications in the future.

“The court is saying that if the government can assert some sort of vague national security concern about a platform or website or whatever, the government can restrain that website, that’s a big deal,” Terry said.