The Pentagon is creating awards to recognize drone pilots who have a direct impact on battle and troops who excel in combat, as part of a broad review of how the military services bestow medals after nearly 15 years of war, defense officials said Wednesday.

The department also will review the Silver Star and Service Cross awards given to troops during the recent Afghanistan and Iraq wars, to ensure service members got the right medal. While officials said that there has been no indication troops were given awards inappropriately, trends show that commanders increasingly approved higher awards as the wars dragged on.

As a result, some officials worried that earlier recipients of the Silver Star and Service Cross medals may have been eligible for the more prestigious Medal of Honor.

There has been broad criticism over how medals are awarded, including differences between the various military services on the qualifications for the medals or the criteria that determine valor or heroism. A move in 2013 by Defense Secretary Leon Panetta to create a medal for drone pilots and cyberwarriors triggered such a backlash that his successor, Chuck Hagel, shelved the idea and ordered reviews of the award systems.

Panetta had tried to create an award for service members who contribute to the fight outside the combat zone. But veterans' groups were irate when the proposal ranked the award a bit higher than the Bronze Star and the Purple Heart.

Under the new Pentagon proposal, there will be an "R" device, which would be a small letter "R" much like the "V" device that troops get for valor. That "R" could be attached to a noncombat ribbon for service members who conduct drone operations from afar that have a direct impact on combat.

A second new award would be the "C" device, which also could be attached to other awards or ribbons. That "C" would be given to troops in recognition of "meritorious service under combat conditions."

Often military members receive ribbons for serving in the war zone -- for example, in Iraq or Afghanistan -- but many of them never see combat. The "C" device would give additional recognition to those who served in those conflicts and were actually in combat.

The Pentagon plans to announce the changes Thursday. The officials weren't authorized to publicly discuss the changes ahead of the announcement and spoke on condition of anonymity.