The United States has fired a new salvo in its rivalry with China, ordering sweeping restrictions against Chinese-owned social media stars TikTok and WeChat.
Here are some key facts about the platforms:
What is WeChat?
It has more than a billion monthly users and is a "super app" used for everything from messaging to ride-hailing and mobile payments, while also serving as a social media platform.
Tencent surpassed Facebook's net worth after it became the first Asian firm to be valued at more than $500 billion (roughly Rs. 37.48 crores) in 2017.
The Hong Kong-listed company now has a market capitalisation of HKD 5.32 trillion (roughly Rs. 51.47 lakh crores), compared with Facebook's $756 billion (roughly Rs. 56.65 crores).
While WeChat is available in various languages, its main user base is in mainland China, where potential rivals such as Facebook's WhatsApp messaging service are barred from competing.
It is also a widely used among the Chinese, and foreigners doing business in the country, to keep in touch with people there.
Tencent has shares in many American companies, including electric-car maker Tesla, social media company Snap, and top games developers such as Riot Games, [Epic Games](https://gadgets.ndtv and Activision Blizzard.
Surveillance on WeChat
WeChat has been dogged by privacy concerns.
The platform censors content for all users registered with Chinese phone numbers, even if they go abroad or switch to an international number, according to a University of Toronto study from 2016.
Another report from the same university in May said accounts not registered in China were also subject to "pervasive content surveillance".
Chinese authorities routinely censor online content and block Western websites such as Facebook, Twitter, and the New York Times.
What is TikTok?
TikTok features kaleidoscopic feeds of short user-made videos of anything from hair-dye tutorials to choreographed dance routines.
It belongs to Chinese tech firm ByteDance and targets the international market while Douyin, a domestic version of the platform, caters exclusively to Chinese users.
TikTok has been downloaded more than 2 billion times since its 2017 launch, according to data from US-based research agency SensorTower.
The app is most popular among teenagers but has found fresh popularity during coronavirus lockdowns around the world as adults look for new ways to pass the time.
It attracted huge followings in the United States, Indonesia and other countries, but it recently became one of 59 Chinese mobile apps banned by India over national security and privacy concerns.
Distancing from China
TikTok has in recent months sought to distance itself from its Chinese owners. It appointed former Disney executive Kevin Mayer, an American, as its new chief executive in May.
It also withdrew from Hong Kong shortly after China imposed a new security law on the city that gave police fresh powers to censor the internet -- a move that analysts said was an effort to avoid the suggestion it was a Chinese-controlled company.
But the app has nonetheless been accused of privacy breaches.
Trump previously set a deadline of mid-September for TikTok to be acquired by a US firm or be banned in the US.