Key Senate defense leaders on Friday are privately pressing Anthropic and the Pentagon to resolve their dispute, a source familiar with the matter told Axios. Why it matters: Pressure has been building on Congress to step in as the Pentagon and Anthropic engage in a prolonged public battle over the limits of the use of Anthropic's Claude AI in classified settings. Driving the news: Senate Armed Services Committee Chair Roger Wicker (R-Miss.) and Ranking Member Jack Reed (D-R.I.), along with Defense Appropriations Chair Mitch McConnell (R-Ky.) and Ranking Member Chris Coons (D-Del.) sent Anthropic and the Pentagon a private letter on Friday urging them to resolve the issue, the source said. Catch up quick : The Pentagon and Anthropic are in a high-stakes clash over the limits Anthropic wants to place on the department's use of its AI model Claude: no mass surveillance or autonomous weapons. Anthropic said Thursday it would not accept the Pentagon's demands. What's next: Pentagon officials have said that Anthropic has until 5:01pm EST on Friday to agree to their demands or face losing their contract.