WASHINGTON—The leaders of the Senate Armed Services Committee have added their names to the growing list of lawmakers asking the Pentagon to lower the ranking of a new medal for cyber fighters.

The proposed Distinguished Warfare Medal would rank ahead of the Bronze Star and Purple Heart.

Sen. Carl Levin, the committee's Democratic chairman, and Sen. Jim Inhofe, the committee's top Republican, asked Defense Secretary Chuck Hagel to reflect on his combat experience in Vietnam. In a letter, they said they were concerned about the message the medal's ranking sends to those who served in harm's way.

The new medal is a sign of the changing nature of war and would honor drone pilots and others who use their technological skills to gather intelligence and kill enemy fighters.