Nato’s purchase of five surveillance drones is “the first concrete sign” the military alliance is moving away from its dependency on the US, a security expert has said.

The new aircraft, unveiled by Nato Secretary General at a ceremony last week in Sigonella air base, Italy, are designed to look for moving objects over large areas of the ground and sea.

They will initially be used to track Russian movements in the Eastern Mediterranean as well as migrants crossing from North Africa.

Designated the RQ-4D Phoenix by Nato, the drones are a version of the US Global Hawk aircraft, one of which was shot down by Iran last year in the Gulf.

Justin Bronk from the Royal United Services Institute says the purchase is “quite a significant acquisition” and a “big departure” for the alliance, although he lamented the time it had taken.

“It is the first concrete sign of Nato taking serious steps to make a dent in the enormous dependency the alliance has on the US,” he said.

“What normally happens is most [alliance members] turn up with some fast jets, maybe [an air to air refuelling] tanker, and the Americans have to do all the target finding, classification, intelligence processing, battle-damage assessment, command and control and so on.”