Britain said Saturday that two Royal Air Force aircraft took part in a 12-hour mission with U.S. and NATO forces to patrol near Russia’s border, following a series of recent Russian drone and aircraft incursions into NATO airspace.

"This was a substantial joint mission with our U.S. and NATO allies," defence minister John Healey said.

"Not only does this provide valuable intelligence to boost the operational awareness of our Armed Forces, but sends a powerful message of NATO unity to (Russian President Vladimir) Putin and our adversaries," Healey added.

An RC-135 Rivet Joint electronic surveillance aircraft and a P-8A Poseidon maritime patrol plane flew from the Arctic region past Belarus and Ukraine on Thursday, supported by a U.S. Air Force KC-135 refueling aircraft.

Britain said the operation followed incursions into the airspaces of NATO countries including Poland, Romania and Estonia.

Earlier this month, European Union leaders backed plans to strengthen the bloc's defenses against Russian drones.