The US Department of Justice has asked the judge in San Francisco to grant the US temporary permission to ban the Chinese chat application WeChat from US app stores.
The US Department of Commerce previously announced that Apple and Google app stores would be banned from offering WeChat from Sunday.
The court then ruled that the ban may restrict freedom of expression too much.
The ministry appealed against that decision. That is scheduled for October 15th. Until then, justice wants to make the app unavailable to American users.
WeChat has some 19 million active users in the US, most Americans of Chinese descent. More than 1 billion people worldwide use the app.
President Donald Trump believes WeChat is a threat to national security, and the app should be banned for that reason.