HARTFORD, Conn. (AP) - The U.S. Department of Interior is not commenting on a request by Connecticut officials for an investigation of the agency's failure to act on agreements between the state and two Native American tribes that are needed for the tribes to build a new casino.

An Interior Department official on Monday referred questions about the request to the Department of Justice, which did not return a message.

U.S. Sens. Richard Blumenthal and Chris Murphy, and U.S. Reps. John Larson and Joe Courtney, asked the Interior Department's Office of Inspector General to investigate Monday.

The Mohegan and Mashantucket Pequot tribes operate casinos in Connecticut and are planning a joint casino in northern Connecticut to compete with an MGM casino in Springfield, Massachusetts, that's expected to open in September.