"It's been 13 days we've been hearing promises, 13 days we've been told we'll be helped in the air, that there will be planes, that they will be delivered to us," Zelensky said on a video broadcast on Telegram.

"But the responsibility for that rests also on those who were not capable to take a decision in the West for 13 days," Zelensky added. "On those who have not secured the Ukrainian skies from the Russian assassins."