TikTok says it will challenge in court an "unconstitutional" law that could result in it being sold or banned in the United States, Paralel.Az reports citing BBC.

President Biden has signed into law a bill which gives the social media platform's Chinese owner, ByteDance, nine months to divest the app or it will be blocked in the US.

The law has been introduced because of concerns TikTok might share user data with the Chinese government - claims it has always denied.

"We are confident and we will keep fighting for your rights in the courts," said TikTok boss Shou Zi Chew.

"The facts, and the Constitution, are on our side... rest assured, we aren't going anywhere."

In a video posted on the platform, he lambasted the bill and called for people to share their stories of how TikTok had improved their lives.

"Make no mistake, this is a ban - a ban on TikTok, and a ban on you, and your voice," he said.

In a separate statement TikTok added that it believed "the facts and the law" were "clearly" on its side.

"The fact is, we have invested billions of dollars to keep U.S. data safe and our platform free from outside influence and manipulation," it said.

The measure was passed as part of a package of four bills which also included military aid for Ukraine, Israel, Taiwan and other US partners in the Indo-Pacific region.

It had widespread support from lawmakers, with 79 Senators voting for it and 18 against.

"For years we've allowed the Chinese Communist party to control one of the most popular apps in America... that was dangerously short-sighted," said Senator Marco Rubio, the top Republican on the Intelligence Committee.

"A new law is going to require its Chinese owner to sell the app. This is a good move for America," he added.

TikTok has said ByteDance "is not an agent of China or any other country". ByteDance insists it is not a Chinese firm, pointing to the global investment firms that own 60% of it.

Experts have told the BBC the bill is "a big deal" but have warned it faces multiple hurdles.

It could take several years before the app is blocked as legal action, likely all the way to the Supreme Court, would delay the process.

In November, a U.S. federal judge in Montana blocked an effort to ban TikTok within the state.

The popularity of the app with young Americans could also be problematic.

“About two in three young people in the US have a TikTok account," said Andrew Przybylski, professor of human behaviour and technology at Oxford University.

“The primary challenge is going to be on freedom of speech and freedom of expression.

"The UN Charter on the Rights of the Child is quite specific: young people have a right to information and a right to play, so I think it can be challenged on those grounds.”

Jennifer Huddleston from the Cato institute, in Washington, said any sale might be delayed because of the “considerable” regulatory scrutiny it would attract.

"Nine months is a rather quick timeframe for this size of a transaction - it's something that is likely to have further regulatory scrutiny even without the requirements in this proposal," she said.

"The question remains - what does it mean to even sell TikTok in the US, is that truly possible, and what would a buyer look like?"

Exactly who would be able to buy and operate it is also a big question - the price would likely be in the tens of billions of dollars, meaning there would be few potential buyers.

Braced for ban

Brooke Erin Duffy, associate professor of communication at Cornell University, said TikTok users in the US had been bracing themselves for a ban "for quite some time".

"The Senate decision injects a heightened level of uncertainty into the livelihoods of countless content creators, influencers, and small business owners," she said.

If it is not sold in time, the app could be blocked in the country - the US says this is because it is concerned TikTok could be used to spy on Americans, or to spread propaganda.

TikTok gathers similar kinds of data to other apps, but the US is concerned this data could fall into the hands of the Chinese government - claims the company has always contested.

Elsewhere, the firm has agreed to suspend its TikTok Lite rewards programme, which pays users to spend time on the app in France and Spain.

European Commissioner Thierry Breton said the feature was "toxic and addictive", particularly when used by children, and threatened to block it unless action was taken.

The EU said its investigation into the feature would continue.