The United States on Friday ordered a ban on downloads of popular Chinese-owned video app TikTok and use of the messaging and payment platform WeChat, saying they threaten national security.

The move, to be implemented Sunday, comes amid rising US-China tensions and efforts by the Trump administration to engineer a sale of TikTok to American investors.

"The Chinese Communist Party has demonstrated the means and motives to use these apps to threaten the national security, foreign policy, and the economy of the US," Commerce Secretary Wilbur Ross said in a statement.

The initiative would ban WeChat, an app with massive use among Chinese speakers, and TikTok from the online marketplaces operated by Apple and Google.

But while WeChat will effectively be shut down from Sunday in the US, existing TikTok user will be able to continue using the app until November 12 -- when it would also face a full ban on its US operations.

President Donald Trump has claimed Chinese tech operations such as TikTok may be used for spying
President Donald Trump has claimed Chinese tech operations such as TikTok may be used for spying GETTY IMAGES NORTH AMERICA / Mario TAMA

But the Commerce Department said if national security concerns over TikTok were resolved before then, the order may be lifted.

TikTok's brand of brief, quirky videos made on users' cellphones has become hugely popular, especially among young people.

The plan follows through on a threat by President Donald Trump, who has claimed Chinese tech operations may be used for spying, and it ramps up the pressure on TikTok parent ByteDance to conclude a deal to sell all or part of TikTok to allay US security concerns.

A deal which appeared to be taking shape would allow Silicon Valley giant Oracle to become the tech partner for TikTok, but some US lawmakers have objected to allowing ByteDance to keep a stake.

The ban on WeChat, owned by Chinese giant Tencent, has the potential for disrupting the widely used social media and financial application.

US officials said in a recent court filing they would not target those using WeChat for ordinary personal communications.