The United States has summoned Russia's ambassador to Washington to lodge a protest over an incident involving a US drone and Russian fighter jets flying over the Black Sea.
Ambassador Anatoly Antonov was summoned after the US military announced that a Russian fighter jet collided with a US drone over the sea on Tuesday morning.
The US said two Russian jets dumped fuel on and flew in front of the drone before one of them struck the drone's propeller. Officials said US forces had to bring the drone down in international waters as the aircraft became uncontrollable.
Moscow denies the collision.
Antonov told reporters at the US State Department that he was told that the actions by the Russian pilots were unprofessional.
He denied that there was any contact between Russian and US aircraft over the sea, and said no weapons were used by Russian fighters.
The ambassador said Russia does not want any confrontation with the US and he called the incident a "provocation" by Washington.
There are concerns that the incident may heighten tensions between the US and Russia.