People gather for a press conference about their opposition to a TikTok ban, as the top court scheduled oral arguments in the case for Jan. 10, 2025, nine days before TikTok faces a ban unless ByteDance divests from the popular app, in Washington, D.C., AFP-Yonhap

The U.S. Supreme Court said on Wednesday that it had agreed to review a U.S. law that mandates a nationwide ban of the popular Chinese-owned video app TikTok if it fails to secure a non-Chinese buyer by January 19.

The arguments over whether the law violates freedom of speech protected by the U.S. Constitution will be heard on January 10.

The court has directed the petitioners to submit a brief by December 27, arguing whether the law, officially known as the Protecting Americans from Foreign Adversary Controlled Applications Act, violates the free speech protections.

The app, owned by Chinese firm ByteDance, has about 170 million active users in the U.S..

If the ban is enforced, cloud-service providers like Google and Apple would be required to remove TikTok from their app stores or face penalties. New users would be blocked from downloading the app and existing users unable to update it on their devices.

"Speech restrictions have survived the Constitution's most demanding standard only in rare and narrow circumstances," TikTok said in an emergency appeal it filed on Monday, requesting a temporary halt on the ban.

TikTok had urged the court to "do what it has traditionally done in free speech cases: apply the most rigorous scrutiny to speech bans and conclude that it violates the First Amendment".

While the Supreme Court did not immediately grant an injunction on Wednesday, pending a full review, its decision to hear the case suggests that a ruling could be issued before the ban takes effect.

Nevertheless, TikTok said it was "pleased" with the order.

"We believe the court will find the TikTok ban unconstitutional, so the over 170 million Americans on our platform can continue to exercise their free speech rights," said Michael Hughes, a spokesperson for the company.

Two other petitioners in the case — civil-rights group BasedPolitics and a coalition of online content creators — had also filed a joint appeal to block the ban in the Supreme Court, citing violations of free speech.

"We're very pleased that the Supreme Court acted so quickly to take up this case, and we'll be hearing arguments before the act takes effect," said Jacob Huebert, a lawyer for BasedPolitics.

"We look forward to making our case to the Supreme Court and we're optimistic that it will enjoin this ban before it can ever take effect," he added.

Also on Wednesday, U.S. Senate Republican leader Mitch McConnell filed an amicus brief in favour of the divest-or-sale law, urging the Supreme Court to deny TikTok any relief.

The TikTok logo is displayed at the social media app company offices in Culver City, Calif., Mar. 16, 2023. AFP-Yonhap

"TikTok clearly desires this court to enjoin the divesture date in the vain hopes that the divesture order will be punted into the next presidential administration where, perhaps, TikTok will find relief from divesture from a less hostile Department of Justice," stated McConnell in the brief.

The Kentucky Republican called on the court not to "countenance such tactics and the public interest counsels in favour of denying an injunction, even in the face of irreparable harm".

"Successive congresses and presidential administrations realized the danger TikTok poses to American national security and went about carefully crafting a response to that adversary threat," McConnell added.

However, U.S. president-elect Donald Trump on Monday suggested that he may be open to reversing the ban.

Trump praised the app for helping him reach out to young American voters, saying TikTok had a "warm spot in my heart".

Later that day, he met with TikTok's CEO Chew Shou Zi at Mar-a-Lago, Trump's private mansion in Florida. Neither side confirmed or denied the meeting, nor did they issue any statements.

Meanwhile, the civil-rights groups the American Civil Liberties Union and the Electronic Frontier Foundation, along with the Knight First Amendment Institute at Columbia University filed an amicus brief on Tuesday, arguing against the law.

The groups said the law was "intended to suppress certain content and viewpoints that many legislators believe could be amplified on TikTok, including the risk of foreign 'propaganda'".

The emergency appeal came after the U.S. Court of Appeals for the District of Columbia Circuit on Friday denied an emergency request from TikTok, its parent company ByteDance and other petitioners to temporarily block the ban pending a Supreme Court review.

Citing national security concerns that Beijing could pressure ByteDance to alter its algorithm and collect personal data in ways that could harm U.S. interests — a claim TikTok has consistently denied — earlier this year Congress passed and Biden signed the Protecting Americans from Foreign Adversary Controlled Applications Act.

The three-judge panel of the U.S. Court of Appeals for the District of Columbia Circuit in upholding the law earlier this month, said "the government acted solely to protect that freedom from a foreign adversary nation and to limit that adversary's ability to gather data on people in the United States".

"That burden is attributable to the [People's Republic of China's] hybrid commercial threat to U.S. national security, not to the U.S. government, which engaged with TikTok through a multi-year process in an effort to find an alternative solution," the opinion stated.

Read the full storyat SCMP.