He seems to go between implying the original empire, and the USSR, however, the last one I saw was an address to a russian program to support young entrepreneurs, where he spends part of his speech discussing the expansion russia. He then tells the story of how peter the great annexed part of sweden. He claimed this wasn’t an invasion of sweden because, at one time, russia claimed that land, so it was merely restoration. It is stuff like this he has been doing. You can find him bringing up this sort of thing in public addresses of all sorts, where he just slips in how making whatever about russia better by restoring the empire, and using these types of stories to justify it.