The price of the never-closed sky for flights over Ukraine was a million refugees from the country and the destruction of the historical centers of Ukrainian cities, Mykhailo Podoliak, adviser to the head of the Office of the President of Ukraine, has said.

"About a million refugees in 7 days of the war and the total destruction of the historical centers of large cities of Ukraine. This is the price of the still uncovered sky over Ukraine," Podoliak wrote on Twitter on Wednesday.