Ukraine said Thursday that one of its F-16 fighter jets made by the United States crashed while repelling a Russian air strike, killing the pilot onboard. A U.S. official confirmed to CBS News the F-16 crashed on Monday.

The announcement marks the first reported destruction of an F-16 in Ukraine, just weeks after Kyiv began taking delivery of the supersonic aircraft.  

Initial reports are the plane wasn’t shot down by the Russians, CBS News has learned.

“F-16 fighters of the Armed Forces of Ukraine were used to repel a missile attack on the territory of Ukraine by the Russian Federation, along with units of anti-aircraft missile troops,” the Ukrainian army said.

“During the approach to the next target, communication with one of the planes was lost. As it turned out later, the aircraft crashed, killing the pilot,” it added.

It did not identify the pilot, but a unit of Ukraine’s air force said one of its pilots, Oleksiy Mes, had died in a crash on Monday while repelling a Russian air attack.

“On 26 August, while repelling a Russian massive combined missile and air strike, Oleksiy destroyed three cruise missiles and one attack drone,” Ukraine’s Western air command unit said.

“Oleksiy saved Ukrainians from deadly Russian missiles. Unfortunately, at the cost of his own life,” it said.

The announcements come as a blow to Ukraine, which had long relied on a fleet of ageing Soviet-era MIG-29 and Sukhoi jets and had asked for the F-16s to defend against intense Russian aerial bombardment.

Moscow fired a wave of attack drones and missiles at Ukraine on Monday this week in what President Volodymyr Zelensky called one of the “largest” attacks of Russia’s two-and-a-half year invasion.

Earlier this month, Zelenskyy said the newly arrived F-16 fighter jets will boost the country’s war effort against Russia.

The American-made F-16 is an iconic fighter jet that’s been the front-line combat plane of choice for the NATO alliance and numerous air forces around the world for 50 years.

President Biden gave the go-ahead in August 2023 for used F-16s to be deployed to Ukraine, though the U.S. won’t be providing any of its own planes.