Video app TikTok said on Monday it had 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 — effectively setting a deadline for a sale of the app to a US company.

“Today we are filing a complaint in federal court challenging the administration's efforts to ban TikTok in the US,” the company said in a blog post.

TikTok argued in the lawsuit that Trump's order was a misuse of 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.

“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 said.

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.

Trump claims 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 has said 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.

“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,” the company said.

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

Trump vs China

Trump has increasingly taken a confrontational stance on China, challenging it on trade, military and economic fronts.

Shortly after Trump announced his moves against TikTok this month, the United States slapped sanctions on Hong Kong's leader over the Chinese security clampdown after last year's pro-democracy demonstrations.

Microsoft and Oracle are possible suitors for TikTok's US operations.

Reports have said Oracle — whose chairman Larry Ellison has raised millions in campaign funds for Trump — was weighing a bid for TikTok's operations in the US, Canada, Australia and New Zealand.

The Trump administration has also given ByteDance a 90-day deadline to divest TikTok before the app is banned in the United States.

The measures move away from the long promoted American ideal of a global, open internet and could invite other countries to follow suit, analysts told AFP previously.

“It's really an attempt to fragment the internet and the global information society along US and Chinese lines, and shut China out of the information economy,” said Milton Mueller, a Georgia Tech professor and founder of the Internet Governance Project.