In 1941 People's Republic of Tuva (Tannu-Tuva Ulus) declared war on Germany. In May, 1943 first volunteers from that Siberian country appeared in the Soviet-German front. One of them, Homushku Churguy-o'ol, a tank driver, became a Hero of a Soviet Union.
In 1944 Tuva was allowed to join Soviet Union.
It still didn't sign a peace treaty or even a cease-fire agreement with Germany. According to Tuvan Constitution - the republic had the right to declare wars and sign peace treaties by it's government decision, even after it became a part of the USSR as an autonomous republic inside Russian Federation. So - officially WWII isn't over yet.
Republic of Tuva