The State Department has approved the possible foreign military sale of four MQ-9B SkyGuardian unmanned aircraft and related equipment to NATO ally Belgium for an estimated cost of $600 million.

The SkyGuardian, a variant of General Atomics’ MQ-9 Reaper, was developed in compliance with European flight regulations for international customers interested in medium-altitude, long-endurance (MALE) remotely-piloted aircraft.

Belgium confirmed its selection of the aircraft in October of last year, describing them as “reconnaissance” assets, suggesting they won’t carry weapons. Belgian defense minister Steven Vandeput said MALE drones “play an increasingly important role in operations, but [at a] European level there is a shortage of this type of aircraft.”

In addition to the aircraft, Belgium has requested to purchase two fixed certifiable ground control stations; five AN/DAS-4 multi-spectral targeting systems; 15 embedded global positioning system/inertial navigation systems; five AN/APY-8 Lynx synthetic aperture radars; and five detect-and-avoid systems. The contract also includes spare and repair parts, personnel training, technical and logistics support services and other related program support.

The proposed sale will “enhance the intelligence, surveillance and reconnaissance (ISR) of the Belgian military in support of national, NATO, United Nation-mandated, and other coalition operations,” according to the State Department. “The current fleet of Belgian Air Component aircraft have proven insufficient to support sustained and persistent ISR operations,” it noted.

Variants of the MQ-9 are used by the U.S., U.K., France, Italy, and Spain. The Netherlands, Australia and India have plans to acquire it.