Video app TikTok on Monday filed a lawsuit challenging the US government’s crackdown on the popular Chinese-owned platform, which Washington accuses of being a national security threat.

As tensions soared between the world’s two biggest economies, US President Donald Trump signed an executive order on August 6 giving Americans 45 days to stop doing business with TikTok’s Chinese parent company ByteDance Ltd – effectively setting a deadline for a sale of the app to a US company.

TikTok argued in the suit that Trump’s order was a misuse of the International Emergency Economic Powers Act because the platform – on which users share often playful short-form videos – is not “an unusual and extraordinary threat”.

The executive order “has the potential to strip the rights of that community without any evidence to justify such an extreme action”, the suit contended.

TikTok said: “We believe the administration ignored our extensive efforts to address its concerns, which we conducted fully and in good faith even as we disagreed with the concerns themselves.”

TikTok’s kaleidoscopic feeds of clips feature everything from dance routines and hair-dye tutorials to jokes about daily life and politics.

The app has been downloaded 175 million times in the US and more than a billion times around the world.

The Trump administration has separately given ByteDance a deadline to divest TikTok before the app is banned in the US.

Trump argues that TikTok could be used by China to track the locations of federal employees, build dossiers on people for blackmail, and conduct corporate espionage.

The company holds firm that it has never provided any US user data to the Chinese government, and Beijing has blasted Trump’s crackdown as political.

The US measures come ahead of November 3 elections in which Trump, behind his rival Joe Biden in the polls, is campaigning hard on an increasingly strident anti-Beijing message.

TikTok said: “The administration failed to follow due process and act in good faith, neither providing evidence that TikTok was an actual threat, nor justification for its punitive actions.

“We believe the administration’s decisions were heavily politicised, and industry experts have said the same.”

A lawsuit filed last week against Trump by a freshly-formed “WeChat Users Alliance” aims a separate August 6 executive order banning the messaging app popular with Chinese speakers.

The suit argued: “The Executive Order singles out people of Chinese and Chinese-American ancestry and subjects them to disparate treatment based on race, ethnicity, nationality, national origin, and alienage.”

The suit contends the order is illegal, and so vaguely worded that it is not clear whether people using the app to message friends or run businesses will be considered law-breakers.

It also says no evidence has been shown that WeChat is a threat to US national security. The alliance said it is not affiliated with WeChat owner Tencent, based in China.