Russian President Vladimir Putin said on Tuesday that Russians were united in a "sacred" fight with the West over Ukraine but the strains of war were evident at one of the most pared back anniversaries of the victory over Nazi Germany in decades.

Putin has repeatedly likened the war in Ukraine — which he casts as a defensive move against a West which wants to carve up Russia — to the challenge Moscow faced when Adolf Hitler invaded the Soviet Union in 1941.

"The decisive battles for the fate of our Motherland have always become patriotic, all-national and sacred," the 70-year-old president told veterans and soldiers assembled on Red Square for the annual Victory Day parade.