President Donald Trump again downplayed risks that TikTok is in danger of being banned in the United States, saying he remains confident of finding a buyer for the app's US business by a Friday deadline.

The hugely popular video-sharing app, which has over 170 million American users, is under threat from a law that passed overwhelmingly last year and orders TikTok to split from its Chinese owner ByteDance or face a ban in the United States.

Motivated by widespread belief in Washington that TikTok is ultimately controlled by the Chinese government, the law took effect on 19 January, one day before Trump's inauguration.

But the Republican president quickly announced a delay that has allowed it to continue to operate; that delay is set to expire on 5 April.

"We have a lot of potential buyers. There's tremendous interest in TikTok," Trump told reporters onboard Air Force One late Sunday.

"We have a lot of people that want to buy TikTok. We're dealing with China also on it, because they may have something to do with it," he said, adding "I'd like to see TikTok remain alive."

Any deal to divest TikTok from ByteDance will require the approval of Beijing, and Trump has said he may offer to reduce tariffs on China as a way to get Beijing's approval for the sale.

Trump, though he supported a ban in his first term, has lately become the app's greatest defender, seeing it as a reason more young voters supported him in November's election.

One of his major political donors, billionaire Jeff Yass, is also a major stakeholder in parent company ByteDance.

ByteDance on board?

Several proposals for TikTok's US business have emerged since the law began to make its way through Congress last year.

But according to The New York Times, citing people involved in coming up with a solution, the most likely fix would see existing US investors in ByteDance roll over their stakes into a new independent global TikTok company.

Additional US investors would be brought on to reduce the proportion of Chinese investors. Trump at one point said the US government could also take a stake through a newly announced national sovereign fund.

Dan Ives of Wedbush Securities told AFP that he believed cloud company Oracle would "play a major role" in such a deal and that "ByteDance will still control and own the algorithm" and have board seats.

Much of TikTok's US activity is already housed on Oracle servers, and the company's executive chairman, Larry Ellison, is a longtime Trump ally who was also floated as a buyer of TikTok's US activity in Trump's first term.

The arrangement would go against the spirit of the law, which is in part based on the premise that TikTok's algorithm can be weaponized by the Chinese against US interests.

But University of Richmond School of Law professor Carl Tobias said he did not expect opposition in the Republican-led Congress, or if Trump ordered another extension to the sale deadline.

"Lawmakers have expressed little opposition to Trump's actions (including ones) which federal judges have ruled violate the Constitution or congressionally-passed statutes," he said.

Other proposals include an initiative called "The People's Bid for TikTok," launched by real estate and sports tycoon Frank McCourt's Project Liberty initiative.

Artificial intelligence startup Perplexity recently expressed interest in buying TikTok as did a joint venture involving YouTube mega-celebrity MrBeast.

When the last deadline passed, in January, TikTok temporarily shut down in the United States, to the dismay of millions of users.