Ukraine will not be able to operate US-built F-16 fighter jets this coming autumn and winter, air force spokesperson Yuriy Ihnat told Ukrainian television late on Wednesday, according to the Reuters news agency.

"It's already obvious we won't be able to defend Ukraine with F-16 fighter jets during this autumn and winter," Ihnat told a joint telethon broadcast by Ukrainian channels.

Ukraine has repeatedly called its Western allies to supply the country with F-16s, which Ukrainian President Volodymyr Zelenskyy said would be a signal that Russia's invasion would end in defeat.

US President Joe Biden said earlier this year that he did not believe that Ukraine needed the F-16s, but ultimately changed his mind and informed G7 leaders that the US will support a joint effort with allies and partners to train Ukrainian pilots on F-16s.

"We had big hopes for this plane, that it will become part of air defense, able to protect us from Russia's missiles and drones terrorism," Ihnat said on Wednesday.