TikTok has filed a lawsuit aiming to block a US law that would ban the video app in the country unless it is sold by its Chinese parent company, Paralel.Az reports citing BBC.

In the filing, the social media company called the act an "extraordinary intrusion on free speech rights" of the company and its 170 million American users.

It said the US had put forward only "speculative concerns" to justify the measure and asked the court to stop it.

President Joe Biden signed the bill into law last month, citing national security justifications.

It followed years of debate in Washington, which has claimed that TikTok's Chinese ownership raises the risk that data on US users could fall into the hands of the Chinese government or be used for propaganda.

TikTok has maintained it is independent of the government, while parent company ByteDance has said it has no plans to sell the business.

The Chinese government has criticised the law as US "bullying" of a foreign firm and signalled it would oppose a sale.

In a briefing with reporters on Tuesday, White House press secretary Karine Jean-Pierre said the law was "not a ban. It is a divestment".

She referred further questions to the Department of Justice which declined to comment.

Under the US law, app stores would be barred from offering TikTok in the US starting in January 2025, unless parent company ByteDance found a buyer. President Biden could extend that deadline by 90 days if talks are making progress.

In the filing with the DC Circuit Court of Appeals on Tuesday, TikTok said the sale requirement was "simply not possible: not commercially, not technologically, not legally. And certainly not on the 270-day timeline required by the Act".

It said the measure had unfairly singled out TikTok, creating a “two-tiered speech regime with one set of rules for one named platform, and another set of rules for everyone else”.

It noted that similar attempted bans, including by former president Donald Trump, had met with trouble in US courts.

The company added that the decision by many politicians, including Mr Biden, to maintain accounts on the app undermined the claims of a security threat.

The US has in the past restricted foreign ownership of broadcast television and radio stations, which require government licences to access public airwaves.

TikTok said its business was distinct, and the government could not dictate ownership of "privately created speech forums".

It said it had spent more than $2bn in an effort to address US concerns, creating safeguards on US data.

Jacob Helberg, who leads a committee charged by Congress with monitoring the national security implications of US-China trade, said TikTok's investments were viewed in Washington as a "deceptive marketing effort".

He said the lawsuit was "unserious" and failed "to address the national security question at hand".

But Ashley Gorski, a senior staff attorney at the American Civil Liberties Union, said TikTok's lawsuit made a persuasive case that the measure was an effective ban, despite White House claims to the contrary, raising free speech concerns.

"The government can't impose this type of total ban unless it's the only way to prevent extremely serious and imminent harm to national security," she said.

"There is no public evidence of harm that would meet the extraordinarily high bar imposed by the first amendment."

She said comments by lawmakers, such as US Senator Mitt Romney, who recently tied the widespread support for the measure in Congress to the desire to shape US perceptions of the Israel-Gaza conflict, would make it harder for the US to defend the law.

But Congressman John Moolenaar, the current leader of the committee that helped to craft the law, said he was confident it would be upheld.

“Congress and the Executive Branch have concluded, based on both publicly available and classified information, that TikTok poses a grave risk to national security and the American people," he said.

"It is telling that TikTok would rather spend its time, money, and effort fighting in court than solving the problem by breaking up with the Chinese Communist Party."

The law aimed at TikTok is part of a number of actions the US has taken against Chinese technology firms in recent years, as tensions rise between the world's two biggest economies.

Separately on Tuesday, the Department of Commerce confirmed it had revoked permissions that had allowed US companies to export certain goods to Chinese technology giant Huawei.

The US sharply limited exports of items such as computer chips to Huawei starting in 2019, citing ties to the Chinese military.

The measures hit the company hard but more recently it appeared to mount a comeback.