Now that the Pentagon is fully funded, Defense Secretary Jim Mattis is ordering the Air Force and the Navy to make sure that 80 percent of their front-line fighter jets are ready for combat by this time next year.

In a memo issued last month, Mattis directs the undersecretary of defense for personnel and readiness to work with the services to develop a plan to increase the mission-capable rate of the inventory of F-35, F-22, F-16 and F/A-18 aircraft no later than Oct. 15.

“In order to preserve the most lethal military in the world … our air assets must prove dominant over the battlefields of both today and tomorrow,” Mattis wrote in the Sept. 17 memo, obtained by the Washington Examiner. The memo was first reported by Defense News.

Mattis says budget shortfalls over recent years have resulted in the combat aviation inventory and supporting infrastructure suffering from “systemic underperformance, overcapitalization, and unrealized capacity.”

Increasing the percentage of planes ready for combat to 80 percent will address the most critical priority first, since those jets form the backbone of U.S. tactical air power.

Mattis also directs the services to find a way to reduce operating and maintenance costs every year, starting in year 2019.

“Progress cannot be limited to these platforms alone,” he writes. “Our military departments must also set and pursue aggressive targets for other enduring fixed- and rotary-wing aviation assets.”

Bringing the mission-capable rates to 80 percent will be more difficult for some planes than others. As of March, the rate for the F-16C fleet was 70.22 percent, while the F-35A and F-22 came in at 54.67 and 49.01 percent, respectively, Defense News reported. The rate for the Navy's F/A-18s was under 50 percent in August, the publication added.