The US Commerce Department said it will issue an order Friday that will bar people in the country from downloading WeChat and TikTok from September 20.
Commerce officials said the ban on new US downloads of TikTok could be still rescinded by President Donald Trump before it takes effect late Sunday as TikTok owner ByteDance races to clinch an agreement over the fate of its US operations.
ByteDance has been in talks with Oracle Corp and others to create a new company, TikTok Global, that aims to address US concerns about the security of its users' data. ByteDance still needs Trump's approval to stave off a US ban.
Commerce officials said they will not bar additional technical transactions for TikTok until November 12, which gives the company additional time to see if ByteDance can reach a deal for its US operations. "The basic TikTok will stay intact until November 12," Commerce Secretary Wilbur Ross told Fox Business Network.
The department said the actions will "protect users in the US by eliminating access to these applications and significantly reducing their functionality."
Oracle shares fell 1.6 per cent after the news in pre-market trading
The Commerce Department order will "deplatform" the two apps in the US and bar Apple Inc's app store, Alphabet Inc's Google Play and others from offering the apps on any platform "that can be reached from within the United States," a senior Commerce official told Reuters.
The order will not ban US companies from doing businesses on WeChat outside the United States, which will be welcome news to US firms like Walmart and Starbucks that use WeChat's embedded 'mini-app' programmes to facilitate transactions and engage consumers in China, officials said.
The order will not bar transactions with WeChat-owner Tencent Holdings' other businesses, including its online gaming operations, and will not prohibit Apple, Google or others from offering TikTok or WeChat apps anywhere outside the United States.
The bans are in response to a pair of executive orders issued by Trump on August 6 that gave the Commerce Department 45 days to determine what transactions to block from the apps he deemed pose a national security threat. That deadline expires on Sunday.
Commerce Department officials said they were taking the extraordinary step because of the risks the apps' data collection poses. China and the companies have denied US user data is collected for spying.