TikTok has filed a lawsuit in US federal court to stop the state of Montana from implementing an overall ban on the video sharing app.

The unprecedented ban, set to start in 2024, violates the constitutionally protected right to free speech, TikTok argued in the suit.

"We believe our legal challenge will prevail based on an exceedingly strong set of precedents and facts," a TikTok spokesperson told AFP.

Montana Governor Greg Gianforte signed the unprecedented prohibition into law on May 17.

Gianforte said on Twitter that he endorsed the ban in order to "protect Montanans' personal and private data from the Chinese Communist Party."

"The state has enacted these extraordinary and unprecedented measures based on nothing more than unfounded speculation," TikTok contended in its lawsuit.

Five TikTok users last week filed a suit of their own, calling on a federal court to overturn Montana's ban on the app, arguing that it violates their free speech rights.

The state is trying to exercise national security power that only the federal government can wield and is violating free speech rights in the process, both suits filed against Montana argue.

TikTok called on the federal court to declare the Montana ban on its app unconstitutional and block the state from ever putting it into effect.

"Montana can no more ban its residents from viewing or posting to TikTok than it could ban the Wall Street Journal because of who owns it or the ideas it publishes," the lawsuit filed by TikTok users contends.

The app is owned by Chinese firm ByteDance and is accused by a some US politicians of being a tool of espionage by Beijing, something the company strenuously denies.

Montana became the first US state to ban TikTok, with the law set to take effect next year.

The app already banned on government devices in the United States, Canada and several countries in Europe. (AFP)