U.S. District Judge Rita Lin in California on Thursday temporarily blocked the Pentagon's blacklisting of Anthropic.

Anthropic alleged in the lawsuit that Defense Secretary Pete Hegseth overstepped his authority when he designated Anthropic a national security supply-chain risk, a label the government can apply to companies that expose military systems to potential infiltration or sabotage by adversaries.

The government violated its right to free speech under the First Amendment of the Constitution by retaliating against its views on AI safety, and violated its Fifth Amendment right to due process by not giving it a chance to dispute the designation, the company said.

Lin, an appointee of former Democratic President Joe Biden, agreed with the company in a 43-page ruling, but said it would not take effect for seven days to give the administration a chance to appeal.

In Thursday's ruling, Lin said the administration's actions did not appear to be directed at the government's stated national security interests, but rather, to punish Anthropic.

"The record supports an inference that Anthropic is being punished for criticizing the government’s contracting position in the press," Lin wrote. "Punishing Anthropic for bringing public scrutiny to the government’s contracting position is classic illegal First Amendment retaliation."

Anthropic refused to allow the Pentagon to use its AI chatbot Claude without restrictions, saying that AI models are not reliable enough to be used safely in autonomous weapons and that it opposes domestic surveillance as a violation of rights.

However, the Pentagon says private companies should not be able to constrain military action.

The Trump administration announced a plan to terminate Anthropic's contracts with federal agencies after the dispute. The Pentagon designated the company as a national security supply-chain risk, which blocked Anthropic from certain military contracts.