The United States on Tuesday condemned a Russian jet's "reckless" collision with one of its drones over the Black Sea that led to the loss of the American aircraft.
"It is not uncommon... for there to be intercepts by Russian aircraft of US aircraft over the Black Sea," National Security Council spokesman John Kirby told journalists, referring to one plane making visual or electronic contact with another.
But this case "is noteworthy because of how unsafe and unprofessional it was, indeed reckless that it was," he said.
Kirby said US President Joe Biden had been briefed about the incident, and that the State Department would express Washington's concerns to Moscow.
"We don't need to have some sort of check-in with the Russians before we fly in international airspace. There's no requirement to do that, nor do we do it," he added.
A Russian Su-27 jet struck the propeller of the MQ-9 Reaper drone, requiring it to be brought down in the water and resulting in the loss of the aircraft, the US military said in a statement.
Prior to the collision, two Su-27s "dumped fuel on and flew in front of the MQ-9," it said.
The United States uses MQ-9 Reapers for both surveillance and strikes and has operated the drones in a variety of locations, including in the Middle East and Africa. Other countries, including Britain and France, also fly Reapers.
Several US MQ-9s have been lost in recent years, including to hostile action.
One was shot down in 2019 over Yemen with a surface-to-air missile fired by Huthi rebels, who also unsuccessfully fired on another of the drones a few days later, the US Central Command said.
According to media reports, a US MQ-9 crashed in Libya in 2022, while another went down during a training exercise in Romania earlier in the year and another was lost over Libya in 2019.