The Trump administration will ban WeChat and video-sharing app TikTok from US app stores, a move that will block Americans from downloading the Chinese-owned platforms over concerns they pose a national security threat.

The bans, announced on Friday (local time), affect only new downloads and updates and are less sweeping than expected, particularly for TikTok, giving its parent group ByteDance some breathing space to clinch an agreement over the fate of its US operations.

WeChat, an all-in-one messaging, social media and electronic payment app, faces more severe restrictions from Sunday.

Existing TikTok users, on the other hand, will see little change until November 12 when a ban on some technical transactions will kick in, which TikTok said would amount to an effective ban.

“We disagree with the decision from the Commerce Department, and are disappointed that it stands to block new app downloads from Sunday and ban use of the TikTok app in the US from November 12,” the company said in a statement.

“We will continue to challenge the unjust executive order.”

TikTok has more than 800 million global users.

President Trump on Friday did not indicate whether he would back a TikTok deal. He said a deal “could go quickly”.

“We have some great options and maybe we can keep a lot of people happy,” he told reporters.

“We have to have the total security from China.”

The ban on new US downloads of the widely popular app could still be rescinded by Trump before it takes effect if ByteDance seals a deal with Oracle that addresses concerns about the security of its users’ data.

The Trump administration has ramped up efforts to purge “untrusted” Chinese apps from US digital networks amid escalating tensions with Beijing on a range of issues from trade and human rights to the battle for tech supremacy.

The ban on WeChat, used by over 1 billion people worldwide, bars the transfer of funds or processing of payments to or from people in the United States through it. Users could also start to experience significantly slower service or sporadic outages from Sunday night.

WeChat developer Tencent Holdings’ called the order “unfortunate” but said it “will continue to discuss with the government and other stakeholders in the US ways to achieve a long-term solution”.

The American Civil Liberties Union said the Commerce order “violates the First Amendment rights of people in the United States by restricting their ability to communicate and conduct important transactions on the two social media platforms.”

The order does not ban US companies from doing businesses on WeChat outside the United States.