Montana Gov. Greg Gianforte tweeted Wednesday that he has banned TikTok in the state "to protect Montanans' personal and private data from the Chinese Communist Party."

The controversial law marks the furthest step yet by a state government to restrict TikTok over perceived security concerns and comes as some federal lawmakers have called for a national ban of TikTok. But it is expected to be challenged in court.

The bill, which will take effect in January, specifically names TikTok as its target, prohibiting the app from operating within state lines. The law also outlines potential fines of $10,000 per day for violators, including app stores found to host the social media application.

Last month, lawmakers in Montana's house voted 54-43 to pass the bill, known as SB419, sending it to Gianforte's desk.

The law comes as TikTok faces growing criticism for its ties to China. TikTok is owned by China-based ByteDance. Many US officials have expressed fears that the Chinese government could potentially access US data via TikTok for spying purposes, though there is so far no evidence that the Chinese government has ever accessed personal information of US-based TikTok users.

This is breaking news and will be updated.