 In the years after the Soviet invasion, most of the 400,000 Japanese civilians who had not already been evacuated during the war left voluntarily under the auspices of the US-USSR Agreement on Repatriation of those left in the USSR, signed in December 1946. Many of the 150,000 Koreans on the island safely returned to mainland Japan, and some went to the northern half of the Korean peninsula; however, roughly 43,000 were not accepted for repatriation by Japan, and also could not be repatriated to the southern half of the Korean peninsula due to the political situation; The Soviet government initially had drawn up plans to repatriate the Koreans along with the Japanese, but the local administration on Sakhalin objected, arguing that incoming Russians from the mainland would not be sufficient to replace the skilled labourers who had already departed. The indecision about the ultimate fate of the Sakhalin Koreans persisted until the outbreak of the Korean War, after which repatriation became a political impossibility. Some sources claim Stalin himself blocked their departure because he wanted to retain them as coal miners on the island. In 1957, Seoul appealed for Tokyo's assistance to secure the departure of ethnic Koreans from Sakhalin via Japan, but Tokyo took no real action on the request, and blamed Soviet intransigence for the lack of progress in resolving the issue; Japan continued its earlier policy of granting entrance only to Sakhalin Koreans who were married to Japanese citizens, or had a Japanese parent.
