The US Department of Defense has approved the sale of four MQ-9 Reaper unmanned aircraft to Spain for $243 million.
The deal would include four MQ-9 Block 5 drones, 20 embedded Global Positioning Systems, two mobile ground control stations, five targeting systems and five radars, the Defense Security Cooperation Agency said in a statement.
"The Spanish Air Force intends to use the MQ-9s for homeland security, peacekeeping, peace enforcement, counterinsurgency and counter-terrorism operations," DSCA said.
The MQ-9 reaper drone is manufactured by General Atomics.
The Reaper, which had a wingspan of 20 metres (66 feet), is already used by Britain, France and Italy and has been ordered by the Netherlands.
The United States uses armed Reapers to fly in combat zones but Spain needs only an unarmed version of the unmanned aerial vehicle (UAV).
The Reaper is capable of flying 24 hours continuously and can reach a maximum altitude of 13,700 metres (45,000 feet).
The Spainish defense ministry has set aside $27 million from the 2016 budget was announced in parliament on Tuesday. It sets aside the amount to buy the drones as well as for two ground stations.
The entire five-year drone programme has a budget of 171 million euros.
Germany, France and Italy decided in May to spend 60 million euros on a technical study for a European drone project proposed by Airbus, France's Dassault and Italy's Alenia Aermacchi of the Finmeccanica group.