The clock is ticking.
Both Chinese-owned TikTok and WeChat will be banned from US app stores from Sunday (September 20).
That's unless President Donald Trump agrees to a last minute deal for the sale of TikTok U.S. from parent company Bytedance.
Now, with less than 48 hours to go, the video-sharing app is squaring up for a fight.
It's asked a U.S. judge to block the ban according to court documents filed late on Friday (September 18).
TikTok and ByteDance filed the complaint in a Washington federal court.
The U.S. announced the ban on Friday blocking people in the U.S. from downloading the two Chinese-owned apps starting on Sunday.
TikTok and Bytedance allege in their complaint that the ban was being introduced for political reasons.
And that it would violate the company's First Amendment rights.
Trump has been locked in a long-running trade dispute with China.
His administration has cited concerns over TikTok's access to the personal data of 100 million Americans.
Both ByteDance and TikTok are seeking a quote "declaratory" judgment and an order "invalidating" Trump's move.
The White House did not immediately respond when Reuters contacted it for comment early on Saturday (September 19).
TikTok has said the ban would "irreversibly destroy" its business in the U.S.