The US has ordered all artificial intelligence (AI) technology from the Chinese firm DeepSeek to be removed from most government systems.
The Department of Homeland Security (DHS) has banned all use of DeepSeek within civilian government agencies, and any technology built with the aid of its AI models.
As a powerful AI model that is open source - meaning it is free to access and less expensive to use - DeepSeek has been seen as a disruptive force in the ongoing AI technology race.
While the DHS notice did not detail the exact security concerns surrounding DeepSeek, the White House has this year criticised AI firms from China.
The DHS, DeepSeek, and the Chinese embassy in Washington DC have been contacted for comment.
The DHS made the order public on Monday, but the ban took effect from the end of July.
The order is specific to civilian agencies, including the Department of the Treasury, the Department of State and the Department of Justice. However, agencies within the Department of Defense are excluded.
The ban follows criticism of Chinese AI from the Trump administration, and from American firms.
White House tech lead Michael Kratsios wrote earlier this year in an internal memo that "malicious exploitation" of American AI firms had been occurring, mainly by rival firms in China.
Anthropic and OpenAI, both of which are poised to list on the public stock market in the coming months, have also claimed to have had their AI models essentially copied by some Chinese AI firms, including DeepSeek.
US president Donald Trump has made clear that he sees China as the key US rival when it comes to development of AI, something he sees as crucial to the future of the country.
DeepSeek has grown in popularity since its initial public release in 2025, with models being in such demand that the company's servers have gone down at times.
While DeepSeek's free chatbot app is one of the most downloaded apps in the Apple App Store rankings, its AI models are also used by US tech companies. Companies like Snowflake, Vercel and OpenRouter all incorporate DeepSeek in their offerings to customers.
Startups have flocked to open source models like DeepSeek.
For a technology or AI developer, using DeepSeek in their work costs a fraction of what a closed model like Google's Google's Gemini, Anthropic's Claude or OpenAI's Codex would.
Similarly, the expense borne by DeepSeek to develop its models has been astronomically less than what it has cost US AI firms to develop their own.
Last year, DeepSeek said it took about $6m (£4.5m) to train the debut version of its model, while the costs associated with OpenAI's GPT-4 were roughly $100m. Such revelations sent tech stocks tumbling.
The most recent version of DeepSeek was released last week. Users of the model have praised it online, saying it beats even the most advanced AI tools out of OpenAI on common tasks for AI tools like computer software coding.