President Donald Trump said Friday that he was ordering every U.S. government agency to "immediately cease" using technology from the artificial intelligence company Anthropic.
Trump in a Truth Social post said there would be a six-month phase-out for agencies such as the Defense Department, which "are using Anthropic's products, at various levels."
Defense Secretary Pete Hegseth, soon after Trump's order, said on X that he was ordering the Pentagon to "designate Anthropic a Supply-Chain Risk to National Security" after the AI startup refused to comply with demands about the use of its technology.
Anthropic said in a statement late on Friday that it is "deeply saddened by these developments." The company said it will challenge any supply chain risk designation in court.
"We believe this designation would both be legally unsound and set a dangerous precedent for any American company that negotiates with the government," Anthropic said.
Anthropic, which signed a $200 million contract with the Pentagon in July, wanted assurances that its AI models would not be used for fully autonomous weapons or mass domestic surveillance of Americans.
The Pentagon, which strongly resisted that request, set a deadline of 5:01 p.m. ET Friday for Anthropic to agree to its demands that the U.S. military be allowed to use the technology for all lawful purposes.
That deadline passed without an agreement.
"Anthropic's stance is fundamentally incompatible with American principles," Hegseth said in a statement on X.
"Their relationship with the United States Armed Forces and the Federal Government has therefore been permanently altered."
"Anthropic will continue to provide the Department of War its services for a period of no more than six months to allow for a seamless transition to a better and more patriotic service," the Defense secretary said. "America's warfighters will never be held hostage by the ideological whims of Big Tech. This decision is final."
Trump, in his Truth Social post, wrote, "The Leftwing nut jobs at Anthropic have made a DISASTROUS MISTAKE trying to STRONG-ARM the Department of War, and force them to obey their Terms of Service instead of our Constitution."
"Their selfishness is putting AMERICAN LIVES at risk, our Troops in danger, and our National Security in JEOPARDY."
"Therefore, I am directing EVERY Federal Agency in the United States Government to IMMEDIATELY CEASE all use of Anthropic's technology," Trump wrote.
"We don't need it, we don't want it, and will not do business with them again!"
Sen. Mark Warner, the Virginia Democrat who is vice chair of the Senate Select Committee on Intelligence, condemned Trump's action.
"The president's directive to halt the use of a leading American AI company across the federal government, combined with inflammatory rhetoric attacking that company, raises serious concerns about whether national security decisions are being driven by careful analysis or political considerations," Warner said in a statement.
"President Trump and Secretary Hegseth's efforts to intimidate and disparage a leading American company — potentially as the pretext to steer contracts to a preferred vendor whose model a number of federal agencies have already identified as a reliability, safety, and security threat — pose an enormous risk to U.S. defense readiness and the willingness of the U.S. private sector and academia to work with the IC [Intelligence Community] and DoD, consistent with their own values and legal ethics," Warner said.
Elon Musk, the mega-billionaire who had been Trump's biggest financial backer in the 2024 election, owns xAI, which aims to compete directly with Anthropic and another major AI company, OpenAI.
Musk in recent weeks has repeatedly bashed Anthropic on his social network X, writing on Friday that the company "hates Western civilization."
Anthropic CEO Dario Amodei said Thursday that his company "cannot in good conscience" allow the Pentagon to use its models without limitation.
In a statement on Thursday, Amodei said, "It is the [Defense] Department's prerogative to select contractors most aligned with their vision. But given the substantial value that Anthropic's technology provides to our armed forces, we hope they reconsider."
"Our strong preference is to continue to serve the Department and our warfighters — with our two requested safeguards in place," Amodei said.
"Should the Department choose to offboard Anthropic, we will work to enable a smooth transition to another provider, avoiding any disruption to ongoing military planning, operations, or other critical missions. Our models will be available on the expansive terms we have proposed for as long as required."
CEO and Co-Founder of Anthropic Dario Amodei speaks during the 56th annual World Economic Forum (WEF) meeting in Davos, Switzerland, Jan. 20, 2026.
Denis Balibouse | Reuters
On Friday, another major AI company, OpenAI, said it has the same "red lines" as Anthropic regarding the use of its technology by the Pentagon and other customers.
"We have long believed that AI should not be used for mass surveillance or autonomous lethal weapons, and that humans should remain in the loop for high-stakes automated decisions," Open AI CEO Sam Altman wrote in a memo seen by CNBC.
OpenAI last year signed its own $200 million contract with the Pentagon.
OpenAI's contract is for AI models in non-classified use cases, which include everyday office tasks.
Anthropic's contract with the Defense Department included classified work.
The Defense Department had no comment on Friday other than pointing to Trump's announcement.
Hegseth, in a post on X, included a screengrab of Trump's post, and cc:ed Anthropic and Amodei with the message, "Thank you for your attention to this matter."
— CNBC's Lora Kolodny contributed to this article