One of Ukraine's F-16 fighter jets crashed while repelling a major Russian attack on Monday, Kyiv's military said, the first such loss reported since the long-awaited arrival of the U.S.-made planes this month.
The jet came down and its pilot died while it was approaching a Russian target, the Ukrainian General Staff said on Thursday on Facebook.
The F-16s had "demonstrated high efficiency" and downed four Russian cruise missiles, it added. Ukraine said Russia launched more than 200 missiles and drones that day targeting the energy sector.
"Connection with one of the aircraft was lost while it was approaching the next target. As it turned out later, the plane crashed, and the pilot died," the statement said.
A U.S. defense official told Reuters that Monday's crash did not appear to be the result of Russian fire, and possible causes from pilot error to mechanical failure were still being investigated.