WASHINGTON: Moscow warned Washington on Wednesday to keep well away from its air space, after a US drone intercepted by Russian jets crashed into the Black Sea, the first known direct confrontation between the superpowers since Russia invaded Ukraine.

Washington and Moscow traded blame for the incident, which took place in international air space near territory Russia claims to have annexed from Ukraine. Moscow called it proof that the United States was directly participating in the war; Washington called it an act of Russian recklessness.

Russia said it would try to recover the drone wreckage from the sea. Washington said it might never be recovered, and steps had been taken to ensure Russia could not gain intelligence from the wreckage. “The Americans keep saying they’re not taking part in military operations. This is the latest confirmation that they are directly participating in these activities - in the war,” Kremlin Security Council Secretary Nikolai Patrushev said.

The US military said two Russian Su-27 fighter planes had approached one of its MQ-9 Reaper drones on a reconnaissance mission over international waters. The fighters harassed the drone and sprayed fuel on it, before one clipped the drone’s propeller, causing it to crash into the sea. “This incident demonstrates a lack of competence in addition to being unsafe and unprofessional,” said James B. Hecker, commander of US air forces in Europe.

White House spokesman John Kirby said US officials had told Russia’s ambassador Anatoly Antonov that Moscow must be more careful: “The message was: Don’t do this again.” According to Russia’s account, there was no collision. The drone crashed after making “sharp manoeuvres”, having “deliberately and provocatively” flown close to Russian air space. Moscow had scrambled its fighters to identify it.