A Russian fighter jet struck the propeller of a U.S. surveillance drone over the Black Sea on Tuesday in a “brazen violation of international law,” causing American forces to bring down the unmanned aerial vehicle, the U.S. said.

But Russia insisted its warplanes didn't hit the MQ-9 Reaper drone. Instead, it said the drone maneuvered sharply and crashed into the water following an encounter with Russian fighter jets that had been scrambled to intercept it near Crimea.

The incident, which added to Russia-U.S. tensions over Moscow’s war in Ukraine, appeared to be the first time since the height of the Cold War that a U.S. aircraft was brought down after an encounter with a Russian warplane.

U.S. President Joe Biden was briefed on the incident by national security adviser Jake Sullivan, according to White House national security spokesman John Kirby. He added that U.S. State Department officials would be speaking directly with their Russian counterparts and “expressing our concerns over this unsafe and unprofessional intercept.”

State Department spokesman Ned Price called it a “brazen violation of international law.” He said the U.S. summoned the Russian ambassador to lodge a protest and the U.S. ambassador to Russia, Lynne Tracy, has made similar representations in Moscow.