US President Donald Trump has granted TikTok a second 75-day extension to comply with a law that requires the hugely popular video app to either sell its US operation or face a ban in the country.

"We do not want TikTok to 'go dark'," Trump wrote on Truth Social. "We look forward to working with TikTok and China to close the Deal." The platform is currently owned by Chinese company ByteDance.

Trump's first extension was granted after he took office in January and was set to expire on Saturday.

The social media platform, which says it has more than 170 million users in the US, must close in the US under a law passed by Congress - unless a buyer is found.

In a statement on Friday, ByteDance said it had been in discussion with the Trump administration, but "an agreement has not been executed".

"There are key matters to be resolved. Any agreement will be subject to approval under Chinese law," a spokesperson said.

Former US President Joe Biden's administration had argued that TikTok could be used by China as a tool for spying and political manipulation.

Congress passed a bipartisan law last year that gave ByteDance six months to sell its controlling stake in TikTok or see the app blocked in the US.

Opponents of a ban have cited freedom of speech as a reason for keeping the platform open.

The new extension comes as the Trump administration tries to broker a deal to bring the social media platform under American ownership, and keep the popular app running in the US.

"The Deal requires more work to ensure all necessary approvals are signed," Trump wrote on his Truth Social platform on Friday.

A TikTok deal was reportedly nearly finalised on Wednesday, but fell apart after Trump on the same day announced sweeping global tariffs, including on China.

ByteDance representatives contacted the White House to inform them China would no longer approve the deal unless negotiations on the tariffs could take place, a source familiar with the deal told CBS News, the BBC's US partner.

The unnamed source said the plan had been for Trump to sign an order initiating a 120-day period for closing the deal, allowing time to finish paperwork and secure financing.

The agreement had won approval from existing investors, new investors, ByteDance, and the US government, but China backed out once Trump imposed the global import taxes, CBS reports.

The Chinese embassy in Washington DC said in a statement that it "opposed practices that violate the basic principles of the market economy".

China faces a 54% aggregate tariff on goods imported into the US, and has retaliated with 34% in counter tariffs.

Reports suggest several potential buyers for TikTok have cropped up in recent days.

Amazon has put in a last-minute offer to the White House to acquire the platform, according to the BBC's US partner CBS, though the firm has declined comment.

Several other potential buyers include billionaire Frank McCourt, together with Canadian businessman Kevin O'Leary. Alexis Ohanian, who co-founded Reddit, has said he has joined Mr McCourt's bid.

Computing giant Microsoft, private equity giant Blackstone, venture capital firm Andreessen Horowitz and search engine Perplexity AI are also reportedly in the running for a stake.

Trump has said his administration was in touch with four separate groups interested in a potential TikTok deal, though he has not named them.

Vice-President JD Vance is spearheading the administration's effort to find a buyer.

The president has also suggested the US could offer a deal where China agrees to approve a TikTok sale in exchange for relief from US tariffs on Chinese imports.

"We hope to continue working in Good Faith with China, who I understand are not very happy about our Reciprocal Tariffs," Trump wrote on Truth Social.

He added that the trade levies are "the most powerful economic tool, and every important to our national security".