Probably, because his entire leadership has had one aim, to eventually bring Ukraine back into Russia. I think this is important to him because he wants to be remembered as a great conqueror that united Russia again. He likes to compare himself to Peter the Great who conquered Crimea and Ukraine in the 17th century. They were part of the Russian 'Empire' until the fall of the USSR in the 90's.

He doesn't seem to understand that these now sovereign countries want nothing to do with Russia ever again!