The US believes that Russia's current air defence and air force capabilities create "not ideal conditions" for supplying Ukraine with US-made F-16 fighter jets at this time.

Lieutenant General Douglas Sims, Director of Operations of the US Joint Staff, noted at a briefing that the conditions under which combat operations take place change over time, "but the conditions right now for the employment of the F-16s are probably not ideal".

"I mean, the Russians still possess some air defense capability. They have air capability. And the number of F-16s that would be provided may not be perfect for what's going on right now," he said.

At the same time, Sims added that since the future will change, "that certainly will dictate how that is employed".

Ukraine's Foreign Minister Dmytro Kuleba suggested that Western fighter jets could appear in Ukrainian skies in early spring 2024.

He later expressed confidence that Ukraine would still receive the F-16s and urged citizens not to be afraid of the Kremlin's threatening statements.

On 11 July, 11 partner countries, together with Ukraine, signed a memorandum defining the conditions for training Ukrainian pilots on the F-16s.