Ukrainian and Western officials now caution that the aircraft once championed by Kyiv as a game changer are unlikely to make an immediate impact on the battlefield.

Dozens of the jet fighters are being transferred to Ukraine and will be operational later this summer, the U.S., Dutch and Danish governments said Wednesday. In total, 80 F-16s will eventually be provided to Kyiv, according to a U.S. official.

NATO members have begun sending F-16 fighter jets to Ukraine, the White House said Wednesday. The initial shipment of the American-made planes, long sought by Kyiv, are being transferred from Denmark and the Netherlands and "will be flying in the skies of Ukraine this summer,

Only six Ukrainian pilots have reportedly been trained by European Nato members to fly F-16 fighter jets due to be delivered to Kyiv next month. Ukraine has been urging its allies for months to send them the jets,