The war between Russia and Ukraine is very tough and proceeds with heavy losses among the Russian invaders, said Mykhailo Podoliak, adviser to the head of the President's Office.

"A very tough war. With heavy losses of the aggressor. As of the morning of March 6, Russia lost about 11,000 servicemen, about 300 tanks, more than 40 aircraft & 48 helicopters. Dozens of artillery systems were destroyed. Ukrainians did all this in 10 days. And they will do more," Podoliak said on Twitter Sunday.