TikTok challenged the law, arguing it violated free speech protections for its 170 million users in the country.
But the Supreme Court’s ruling means the US version of the app will be removed from app stores and web hosting services unless a buyer is found in the coming days.
It was believed that the ban would not affect TikTok users who had already downloaded the app on their phones.
But a fresh statement from TikTok late on Friday indicated that it could be immediately unavailable to all existing users, as well as those looking to download it.
President Joe Biden’s term is set to end on Monday, and Donald Trump is due to be sworn in as the next president. Earlier, the White House said that it would be up to the next president to implement the law.
Trump has said he opposes the ban, after initially supporting the move. “My decision on TikTok will be made in the near future, but I have to have time to consider the situation,” he said on Friday.
ByteDance has vowed not to sell TikTok and said it plans to shut down the app in the US on Sunday unless there is a delay.
Democratic and Republican lawmakers voted to ban the video-sharing app last year over concerns about its ties to the Chinese government. TikTok has repeatedly said it does not share information with Beijing.
