WASHINGTON - The Supreme Court seemed inclined on Jan 10 to uphold a law that would force a sale or ban the popular short-video app TikTok in the United States by Jan 19, with the justices focusing on the national security concerns about China that prompted the crackdown.

During over two hours of arguments, the nine justices pressed lawyers representing TikTok, its Chinese parent company ByteDance and app users about the risk of China’s government exploiting the platform to spy on Americans and carry out covert influence operations - while also probing free speech concerns.

“Are we supposed to ignore the fact that the ultimate parent is, in fact, subject to doing intelligence work for the Chinese government?“ conservative Chief Justice John Roberts asked Mr Noel Francisco, a lawyer for TikTok and ByteDance.

The companies and users sued to block the law passed by Congress with strong bipartisan support in 2024 and signed by outgoing Democratic President Joe Biden, whose administration is defending it. They appealed a lower court’s ruling upholding the law and rejecting their argument that it violates the US Constitution’s First Amendment protection against government abridgment of free speech.

Some justices raised apprehensions about the law’s impact on free speech, but their prevailing concern seemed centred on the national security implications of a social media platform with foreign owners that collects data from a domestic user base of 170 million Americans, about half the US population.

Conservative Justice Brett Kavanaugh asked lawyer Mr Francisco about potential long-term risks of China gathering data on users, especially those who flocked to the app at a young age, and using “that information over time to develop spies, to turn people, to blackmail people - people who a generation from now will be working in the FBI or the CIA or the State Department.”

The Supreme Court’s consideration of the case comes at a time of rising trade tensions between the world’s two biggest economies. Republican Donald Trump, due to begin his second term as president on Jan 20, opposes the ban.

Trump on Dec 27 urged the court to put a hold on the Jan 19 deadline for divestiture to give his incoming administration “the opportunity to pursue a political resolution of the questions at issue in the case.”

Mr Francisco called the app one of the most popular speech platforms for Americans and said it would essentially shut down on Jan 19 without a divest...