Anthropic is asking a federal court in Washington, D.C. to rehear its appeal in a case concerning the Pentagon's blacklisting of the company's AI models.

"The Secretary of War branded Anthropic — an American AI company whose models help defend the nation— a national-security 'supply chain risk' because it declined to permit its models to be used for mass surveillance of Americans or lethal autonomous warfare and publicly explained those AI-safety commitments," Anthropic attorneys wrote in the petition filed on Tuesday. "A divided panel upheld that extraordinary designation."

The Defense Department, led by Pete Hegseth, applied the supply chain risk label in March, a move that blocked defense contractors from using the company's technology in their work with the agency. That came after a breakdown in negotiations about how the military could use Anthropic's Claude AI models.

Anthropic sued the Trump administration in an effort to undo that action. In September, the D.C. Circuit upheld the Pentagon's blacklisting. The 2-1 decision rejected Anthropic's argument that the Department of Defense's ban on its Claude models was arbitrary, unauthorized and unconstitutional.

Anthropic's attorneys wrote in the Tuesday filing that the court ignored "straightforward evidence the designation was retaliation for Anthropic's speech about AI safety."

Before the clash between the two sides spilled into the public's view earlier this year, Anthropic served as an early partner across many U.S. agencies, including the DOD. Anthropic signed a $200 million contract with the Pentagon in July of 2025, but as the company began negotiating Claude's deployment on the DOD's GenAI.mil AI platform that September, talks collapsed.

A representative from Anthropic declined to comment beyond the filing. The Pentagon didn't immediately respond to a request for comment.

— CNBC's Ashley Capoot contributed to this report.