The NKVD arrested Meretskov at the start of invasion of the Soviet Union. Released two months later, he returned to command the 7th Army and later the Volkhov Front during the 1941–1944 siege of Leningrad. He commanded the Karelian Front from February 1944, notably the Petsamo–Kirkenes Offensive of October 1944. From April 1945 he was assigned to the Far East, where he commanded a front during the Soviet invasion of Japanese Manchuria. During the war he reached the rank of Marshal of the Soviet Union.