The US Supreme Court on Friday upheld a federal law banning the popular video-sharing app TikTok. The law will go into effect on Sunday unless TikTok's Chinese parent company, ByteDance, sells the platform.

TikTok argued that the law violated free speech rights. However, the court cited national security concerns for its decision.

The justices wrote, "TikTok's scale and susceptibility to foreign adversary control, together with the vast swaths of sensitive data the platform collects, justify differential treatment to address the government's national security concerns."

The app reportedly has about 170 million users in the US. Reaction to the ban was mixed.

A student at Arizona State University said: "I'm not going to be sad per se, maybe a little frustrated because I'm going to have so much time. What am I going to do with that time?"

Another student at the school said, "I feel like it'll help me, like, prioritize more other stuff than, like, just scrolling TikTok because it does consume a lot of my time."

Some self-proclaimed "TikTok refugees" have fled to another Chinese social media platform, RedNote. Media outlets report that it has gained nearly 3 million US users over a single day.

Reports also say tech billionaire Elon Musk, who wields influence in the incoming administration of President-elect Donald Trump, wants to buy TikTok.

Trump submitted an opinion to the court last month requesting a delay in the ban. He has proposed resolving the issue through negotiations and said after the ruling he will make a decision about the matter "in the not-too-distant future."

TikTok CEO Shou Zi Chew thanked Trump for "his commitment to work with us to find a solution that keeps TikTok available in the United States."

President Joe Biden, whose last full day in office is on Sunday, said the decision to enforce the ban "will be made by the next president anyway."