US President Donald Trump has signed an executive order to ban transactions with TikTok’s parent company ByteDance.
The executive order says the US “must take aggressive action against the owners of TikTok to protect our national security”.
Under the order, beginning in 45 days, any US transaction with ByteDance will be prohibited.
TikTok denies accusations it is controlled by or shares data with the Chinese government.
On Thursday night, the US president also issued a follow-up executive order taking similar action to ban WeChat, an app owned by China-based tech giant Tencent.
What did Trump say?
In both executive orders, he says he has found “additional steps must be taken to deal with the national emergency with respect to the information and communications technology and services supply chain”.
He adds: “The spread in the United States of mobile applications developed and owned by companies in the People’s Republic of China (China) continues to threaten the national security, foreign policy, and economy of the United States.”
He refers to both apps as a “threat”. Both orders say any unspecified “transactions” with the apps’ Chinese owners or their subsidiaries will be “prohibited”.
The orders cite legal authority from the National Emergencies Act and the International Emergency Economic Powers Act.
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Media captionWATCH: What’s going on with TikTok?
The text of Mr Trump’s order says TikTok’s data collection could allow China to track US government employees and gather personal information for blackmail, or to carry out corporate espionage.
He notes that reports indicate TikTok censors content deemed politically sensitive, such as protests in Hong Kong and Beijing’s treatment of the Uighurs, a Muslim minority.
The US president says the Department of Homeland Security, the Transportation Security Administration (which oversees US airport screening) and the US Armed Forces have already banned TikTok on government phones.
ByteDance and Tencent have declined so far to comment.
What’s the background?
Since Mr Trump vowed last Friday to ban TikTok, tech giant Microsoft has said it is in talks to acquire the Chinese app’s US operations.
Mr Trump said this week he would support the sale to Microsoft as long as the US government received a “substantial portion” of the sales price.
But he warned he would ban TikTok in the United States from 15 September.
Thursday’s executive orders order came a day after US Secretary of State Mike Pompeo said he was expanding a US crackdown on Chinese technology to personal apps, naming TikTok and WeChat.
The US government took action last year against two Chinese communications companies, Huawei and ZTE, including locking them out of government contracts.
Mr Trump has been waging a trade war against China and he blames the country for the global coronavirus pandemic, which has crippled the American economy, jeopardising the US president’s re-election prospects this November.
What is TikTok?
The fast-growing app – which has up to 80 million active monthly users in America – has exploded in popularity in recent years, mostly with people under 20.
They use the app to share 15-second videos that often involve lip-synching to songs, comedy routines and unusual editing tricks.
These videos are then made available to both followers and strangers. By default, all accounts are public, although users can restrict uploads to an approved list of contacts.
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Media captionWhat is TikTok?
TikTok also allows private messages to be sent but this facility is limited to “friends”.
The app is reported to have around 800 million active monthly users, with its biggest markets having grown in the US and India.
Though as Mr Trump notes in his executive order, India has already blocked TikTok, as well as other Chinese apps.
Australia, which has already banned Huawei and telecom equipment-maker ZTE, is also considering banning TikTok.
What is WeChat?
WeChat is sometimes described as being a social network, but it’s really so much more – offering ways to make payments, run additional mini-programs, find dates and get the news, in addition to messaging and other social activities.
It is perhaps best thought of as being a kind of secondary operating system that sits on top of iOS or Android.
It is also viewed as being a key instrument in China’s internal surveillance apparatus – requiring local users who have been accused of spreading malicious rumours to register a facial scan and voice print.
But in addition, it is allegedly commonly used by the Chinese Communist Party to pump propaganda to the Chinese diaspora.
A seminar held earlier this year by the Australian Strategic Policy Institute think tank discussed how groups within the app would be used to recommend holiday destinations, restaurants and the like on a day-to-day basis, but then switch to spreading political messages in line with Beijing’s thinking at critical times.