The U.S. Department of State has approved a possible sale to Belgium of MQ-9B drones at an estimated cost of $600 million, the Defense Security Cooperation Agency said.

Belgium has requested the purchase of four MQ-9B SkyGuardian Remotely Piloted Aircraft and related equipment, as well as technical and logistics support which will enhance “the intelligence, surveillance, and reconnaissance (ISR) capability of the Belgian military in support of national, NATO, United Nations-mandated, and other coalition operations,” DSCA said in a Tuesday, March 26 release.

The program cost includes 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 as well as personnel training and U.S. government and contractor engineering and other support.

“Belgium intends to use these defense articles and services to provide for the defense of its deployed troops, regional security, domestic security, and interoperability with the U.S./NATO partners,” DSCA said.

The principal contractor will be General Atomics Aeronautical Systems, Inc.

On Thursday, the U.S. awarded General Atomics a $123 million contract to produce four MQ-9 Reaper drones for the Netherlands, a sale first approved in 2015.

Launched in 2001, the MQ-9 was the first remotely-piloted unmanned aerial vehicle designed for medium-altitude long-endurance missions and can operate autonomously for both intelligence, surveillance and reconnaissance missions and precision strikes.

The SkyGuardian variant was developed to meet NATO standards, will have an endurance time of 40 hours and be capable of surviving both bird and lightning strikes, according to the company.

It can also be equipped with a Detect and Avoid system “including space, weight, and power provisions to enable the retrofitting of an airborne Due Regard Radar (DRR) for operation in non-cooperative airspace.”

The MQ-9 is used by the U.S. Air Force and Department of Homeland Security, NASA, and the air forces of France, Italy, Spain and the United Kingdom. In addition to Belgium and the Netherlands, Australia and India have plans to acquire variants of the drone.