TikTok has disconnected access to its users in the United States after no action was taken shortly before a national ban was to take effect, with President-elect Donald Trump unable to intervene until he takes office.
"A law banning TikTok has been enacted in the US," said a message to users attempting to use the app on Saturday at about 10.45pm ET (Sunday, 2.45pm AEDT).
"Unfortunately, that means you can't use TikTok for now."
The TikTok app was also not available in the US for download in the Google and Apple app stores.
TikTok had warned on Friday (local time) ahead of the 19 January ban that it would "go dark" unless it received assurance that distributors — such as Google and Apple — would not be penalised for offering the popular social media app for download.
The White House said any decision would fall to the incoming Trump administration. The president-elect is .
Chinese-owned TikTok has about 170 million American users.
It was not clear if any US users could still access the app, but it was no longer working for many users and people seeking to access it through a web application were met with the same message that TikTok was no longer working.
Other apps owned by ByteDance, including video editing app Capcut and lifestyle social app Lemon8, were also offline and unavailable in US app stores as of late Saturday (local time).
TikTok ban reprieve 'likely'
Trump earlier said he would "most likely" give TikTok a 90-day reprieve from a potential ban after he takes office on Monday.
"The 90-day extension is something that will be most likely done, because it's appropriate," Trump told NBC. "If I decide to do that, I'll probably announce it on Monday."
Trump's promise was cited in a notice posted to users on the app.
"We are fortunate that President Trump has indicated that he will work with us on a solution to reinstate TikTok once he takes office. Please stay tuned," the notice said.
Why has TikTok been banned in the US?
A law passed last year, which found strong bipartisan support,
The platform had until Sunday to cut ties with its China-based parent ByteDance or shut down its US operation to resolve concerns it poses a threat to national security.
On Friday, White House Press Secretary Karine Jean-Pierre released a statement saying: "TikTok should remain available to Americans, but simply under American ownership or other ownership that addresses the national security concerns identified by Congress in developing this law."
TikTok's chief executive has said the company has never, and would never, share US user data with the Chinese government.
The Chinese embassy in Washington on Friday accused the US of using unfair state power to suppress TikTok.
"China will take all necessary measures to resolutely safeguard its legitimate rights and interests," a spokesperson said.
The alternative apps
Uncertainty over TikTok's future sent users — mostly young people — scrambling to alternative apps, including another Chinese-owned app called Xiaohongshu, or RedNote in English.
The app gained nearly three million users in the US in one day earlier this week, as self-proclaimed 'TikTok refugees' joined.
Prior to Monday, Red Note had fewer than 700,000 users in the US and saw a sharp rise to 3.4 million daily active users in the space of a day.
Social media rivals Meta and Snap also saw their share prices rise this month ahead of the ban.
Many TikTok users have posted opinions on social media platform X — formerly Twitter — about being shut out of the app.
Users on Instagram also fretted about whether they would still receive merchandise they had bought on TikTok Shop, the video platform's e-commerce arm.
