Kremlin foreign policy advisor Yuri Ushakov said on Monday that he thought it likely that North Korean soldiers would take part in next year's Moscow's Red Square parade to commemorate the Soviet victory over Nazi Germany in World War Two.
Ukraine says North Korean soldiers have fought on Russia's side against Ukrainian troops trying to hold territory in Russia's Kursk region.
Moscow has neither confirmed nor denied the presence of North Korean troops on its soil, Reuters reported.
Russian President Vladimir Putin and North Korean leader Kim Jong Un signed a "Comprehensive Strategic Partnership Treaty" during Putin's visit to Pyongyang in June.
The pact includes a mutual defence pact for immediate military assistance if either faces armed aggression.