The Trump administration has backed the Pentagon’s decision to blacklist AI company Anthropic, calling the move justified and lawful in a recent court filing. The case comes after the company challenged the decision in a high-profile lawsuit, arguing that its rights were violated.

The dispute began when Defense Secretary Pete Hegseth labeled Anthropic as a national security supply chain risk on March 3. The decision followed a breakdown in negotiations between the Pentagon and the company over how its AI technology should be used. Anthropic, known for developing the AI assistant Claude, had refused to remove safety restrictions that prevent its technology from being used in autonomous weapons or domestic surveillance.

According to the administration’s legal filing, this refusal was considered a business decision rather than protected speech under the First Amendment. Officials argued that the government’s action was not aimed at limiting the company’s expression but was instead based on national security and contract-related concerns. The filing also stated that no one had tried to restrict Anthropic’s ability to express its views.

Anthropic has taken the matter to a federal court in California, seeking to block the Pentagon’s decision while the case continues. The company claims the designation is unlawful and violates its free speech and due process rights. It also argues that the government did not follow proper procedures required under federal law when making such a decision.

President Donald Trump supported the Pentagon’s move, which limits Anthropic’s access to certain military contracts. While the restriction applies to a specific set of government deals, company executives warn it could harm its reputation and lead to significant financial losses.

The conflict highlights growing tensions between AI companies and governments over how advanced technologies should be used. Anthropic has maintained that current AI systems are not safe enough for autonomous weapons and has consistently opposed domestic surveillance on ethical grounds.

In addition to the California case, the Pentagon has issued a separate designation under another law that could expand the restrictions across the entire federal government. Anthropic is also challenging that action in a second lawsuit filed in a Washington, D.C. appeals court.