AUGUSTA — Maine’s two U.S. senators are asking that the USS Portland, an amphibious transport dock ship named after the city of Portland, Ore., also be named in honor of Portland, Maine.

Republican Sen. Susan Collins and independent Sen. Angus King on Thursday sent a letter to Navy Secretary Ray Mabus making the request.

Their letter says the senators were surprised that the ship’s naming announcement did not state that the ship was also named in honor of the city of Portland, Maine. The letter asks that the ship also be named in honor of Maine’s largest city, “consistent with the long history and tradition of U.S. Navy ships bestowed with the name USS Portland.”

It mentions the “rich naval history” of Portland and South Portland, Maine.