Move follows weeks of tension between Pentagon and Anthropic over AI guardrails.

The Wall Street Journal reports Trump Ends Federal Use of Anthropic’s AI as Pentagon Labels It Security Risk

The federal government will stop working with Anthropic and designate the artificial intelligence company a supply-chain risk, a dramatic escalation of the government’s clash with the company over how its technology can be used by the Pentagon.

“I am directing every federal agency in the United States government to immediately cease all use of Anthropic’s technology. We don’t need it, we don’t want it and will not do business with them again!” President Trump said in a post on Truth Social.

The Defense Department and other agencies using Anthropic’s Claude models will have a six-month phaseout period, he said, adding that there would be civil and criminal consequences if the company isn’t helpful during the transition.

Trump’s announcement came shortly before the Pentagon’s Friday afternoon deadline for Anthropic to agree to let the military use its models in all lawful-use cases, a concession the company had refused to make. “We cannot in good conscience accede to their request,” Anthropic Chief Executive Dario Amodei said on Thursday.

Trump and administration officials have attacked the company for that stance, while also taking exception to its push for AI regulations and its links to organizations that are big Democratic donors.

Shortly after the deadline, Defense Secretary Pete Hegseth said on X that he is designating the company a supply-chain risk, impairing its ability to work with other government contractors.

Hegseth had previously threatened the move. The designation is normally used for companies from foreign adversaries like China that pose security threats.

Depending how aggressively the Defense Department enforces the restriction, it could mean that other companies working with the Pentagon will have to show that they don’t use Claude at all, a threat that could hit swaths of Anthropic’s business. “America’s warfighters will never be held hostage by the ideological whims of Big Tech,” Hegseth said in his post.

AI and security experts said the administration’s actions could have a chilling effect for other businesses considering working with the Pentagon or other agencies.

“This is a dark day in the history of American AI. The message sent to the business community and to countries around the world could not be worse,” said Dean Ball, a former Trump administration AI adviser who is now a senior fellow at the Foundation for American Innovation, a center-right think tank. He had called for the administration not to use the supply-chain risk designation.

Ball said that Anthropic partners and investors including Nvidia, Amazon and Google might have to divest from the company or stop working with it if they want to continue working with the Pentagon. Some legal analysts have said it only applies to the work companies do with the military, not all private-sector business.

“It basically says to any startup that’s contemplating dipping its toe in the Defense Department water that they’re going to grab your ankle and pull you all the way in,” said Gregory Allen, a senior adviser focused on AI at the Center for Strategic and International Studies.

Read More: Trump Bans Federal Use Anthropic AI as a Security Risk