Ukraine has received its first batch of U.S.-made F-16 fighter jets, Ukrainian President Volodymyr Zelenskyy said on Sunday, showing journalists the aircraft that Kyiv hopes will help beat Russian forces.

"We often heard the word 'impossible' ... Now it is a reality. Reality in our skies. F-16s in Ukraine. We made it happen," Zelenskyy said, adding that "the number of F-16s we have in Ukraine, the number of pilots who have already been trained, is not enough." 

The arrival of the jets is a milestone for Ukraine after many months of waiting, though it remains unclear how many are available and how much of an impact they will have in enhancing Kiev's capabilities.

(With input from agencies)