COLOGNE, Germany – NATO’s top general in Europe has declared initial operational capability of the alliance’s five-strong fleet of surveillance drones stationed in Sicily, Italy.

The unmanned aircraft and associated ground equipment make up the NATO Allied Ground Surveillance program. Started nine years ago, its goal is to provide all member countries with an aerial picture of worldwide threats, especially in locations close to alliance borders.

The mission-ready proclamation comes after NATO received its fifth and final aircraft for the fleet of modified Northrop Grumman RQ-4D Gobal Hawks at Sigonella Air Base last November. There are also enough trained personnel assigned to the program for initial operations to commence, according to a NATO spokesman.

U.S. Air Force Gen. Tod Wolters, the supreme allied commander Europe, called the fleet’s completion “a significant milestone towards improved sensing of the environment.”

NATO Secretary General Jens Stoltenberg on Feb. 15 mentioned the AGS program as an example of the alliance’s desire to field “disruptive” and “emerging” technology.

“They will enable us to monitor wide areas from the sky, providing a comprehensive picture of conditions on the ground at any time,” he told reporters in Brussels, referring to the unmanned aircraft, dubbed “Phoenix” in NATO parlance. “They can even identify improvised explosive devices. So they are a very useful tool in providing information, reconnaissance, and intelligence.”

While top alliance officials conferred an initial, mission-ready status to the program today, the aircraft started flying test missions to the Baltics and the southern and eastern Mediterranean last summer that yielded useful data, a NATO spokesman told Defense News.

The alliance’s military headquarters in Europe, SHAPE, will help determine future missions, while planning and execution fall under Allied Air Command at Ramstein Air Base, Germany, the spokesman explained.

Routine operations of the fleet are expected to test the promise of cross-border collaboration among allies on mixing unmanned aircraft and regular civilian traffic in their respective air space. Diplomatic clearances for overflights are still necessary at the moment, though the plan is to broker some kind of standing authorization, the spokesman said.

With additional reporting by Vivienne Machi in Stuttgart, Germany