The agencies should remove DeepSeek and its affiliated products, as well as third party products and services developed using DeepSeek, from their IT systems, the Department of Homeland Security said in a notice made public on Monday.

The department’s order, dating back to late July, also blocks civilian agencies from procuring DeepSeek products and services. DeepSeek is one of China’s leading and best-known AI companies and its open-source models are widely available in countries including the United States. They are mostly free to use.

The notice in the Federal Register alleges that DeepSeek’s models “present multiple threat vectors.” It said concerns include that its servers are located in China and that Chinese authorities’ could potentially access private company infrastructure and sensitive U.S. data.

In Beijing, Chinese Foreign Ministry spokesperson Mao Ning said China will “will resolutely safeguard the legitimate rights and interests of Chinese companies” when asked at a regular press conference about the U.S. ban.

“China consistently opposes the overstretching of the concept of national security and the politicizing of science, technology, economic and trade issues,” she told reporters at a routine briefing.

DeepSeek did not immediately respond to a request for comment.

U.S. President Donald Trump and Chinese President Xi Jinping are set to meet in mid-November on the sidelines of the APEC, or Asia-Pacific Economic Cooperation, leaders’ summit in Shenzhen, China.

AI is expected to be on the agenda.

China and the U.S. have recently made progress in some collaboration on AI governance, including a U.S. proposal for setting up of a notification system on national security-related incidents, but the two countries are still at odds on many issues.

U.S.-led restrictions still ban China from accessing some of the world’s most advanced AI chips and the machines that make them. Last week, Beijing rolled out new proposed plans to restrict exports of certain advanced AI models.

The U.S. has also said Chinese AI startups including DeepSeek engaged in large-scale “distillation,” or extraction of capabilities, from frontier American AI models, claims that Beijing has dismissed.

Earlier this year, the U.S. Federal Communications Commission announced it was barring imports of new foreign-made humanoid robots in a move seen as targeting China.