Washington, May 8 (IANS): TikTok, an online video entertainment platform, and its Chinese parent company ByteDance have filed a legal challenge against the US government over a law forcing ByteDance to sell off the ultra-popular app or face a nationwide ban in the country.

US President Joe Biden signed a TikTok ban bill into law last month after it was passed by both houses of US Congress.

"Congress has taken the unprecedented step of expressly singling out and banning TikTok: a vibrant online forum for protected speech and expression used by 170 million Americans to create, share, and view videos over the Internet," said TikTok in the petition filed on Tuesday in the Court of Appeals for the District of Columbia Circuit, adding that "For the first time in history, Congress has enacted a law that subjects a single, named speech platform to a permanent, nationwide ban, and bars every American from participating in a unique online community with more than 1 billion people worldwide."

TikTok pointed out in the petition that the law -- the Protecting Americans From Foreign Adversary Controlled Applications Act -- is "unconstitutional", Xinhua news agency reported.

"Banning TikTok is so obviously unconstitutional, in fact, that even the Act's sponsors recognized that reality, and therefore have tried mightily to depict the law not as a ban at all, but merely a regulation of TikTok's ownership," said TikTok.

The law only gives ByteDance 270 days to sell TikTok to a non-Chinese buyer, with the possibility of a 90-day extension if the US President determines it necessary.

"But in reality, there is no choice," said TikTok, noting that the "qualified divestiture" demanded by the Act to allow TikTok to continue operating in the US is simply not possible: not commercially, not technologically, not legally.