The Trump administration is asking a federal appeals court to reinstate the prohibitions against Chinese-owned social media app WeChat in the U.S. that were blocked by a judge last month.

The administration filed a notice of appeal Friday in the San Francisco federal court where a group of U.S. WeChat users won a preliminary injunction against what they said amounted to an outright ban of WeChat, which is used by millions of Chinese-speaking Americans.

President Donald Trump has said WeChat, owned Tencent Holdings Ltd., as well as TikTok, owned by ByteDance Ltd., are a national security threat because the Chinese parent companies can use the apps to spy on users and steal their private data.