'Hostile' warning as US drone crash adds to tensions

Moscow warned against "hostile" US flights as tensions simmered after a Russian fighter jet was accused of colliding with an American drone on Tuesday over the Black Sea.

Though Russia has denied its Su-27 plane had any contact with an unmanned Reaper drone, Kyiv said the incident over international waters was a Kremlin attempt to widen the Ukraine conflict.

"We assume that the United States will refrain from further speculation and stop flights near Russian borders," Russia's ambassador to Washington, Anatoly Antonov, said. "We consider any action with the use of US weaponry as openly hostile."

US Defense Secretary Lloyd Austin called for Moscow to operate its aircraft safely and professionally, saying the incident is part of a pattern of "aggressive, risky and unsafe actions by Russian pilots in international airspace."

Russia's defense ministry said it scrambled fighter jets following the detection of a US drone over the Black Sea and denied causing the crash.

The Pentagon said its drone was on a routine mission when it was intercepted "in a reckless, environmentally unsound and unprofessional manner."

The US uses MQ-9 Reapers for both surveillance and strikes and has long operated over the Black Sea, keeping an eye on Russian naval forces.

The Reaper drone was "unflyable and uncontrollable so it was brought down," the Pentagon added.

But for Ukraine, the incident was evidence that Russian President wanted to raise the stakes of the conflict in Ukraine and lure in Washington. "The incident with the American MQ-9 Reaper UAV is Putin's way of signalling his readiness to expand the conflict to involve other parties," Ukraine's National Security and Defense Council secretary Oleksiy Danilov said.

Russia's military campaign in Ukraine has led to heightened fears of a direct confrontation between Moscow and the NATO alliance, which has been arming Kyiv.