The invasion of the Russian army has turned Ukrainian children into "children of war" who are forced to spend the night in basements due to the threat of rocket attacks and watch the armed occupiers, adviser to the head of the President's Office Mykhailo Podoliak said.

"The Russians have turned our kids into 'the children of war.' Those who sleep in basements, are constantly under rocket fire, who see armed invaders robbing, shooting, looting," Podoliak said on Twitter on Tuesday.