On February 7, 1855, Japan and Russia signed the Treaty of Commerce, Navigation and Delimitation, which confirmed the boundary between the islands of Etorofu and Uruppu. The Northern Territories, consisting of four islands of Etorofu, Kunashiri, Shikotan and Habomai, are an inherent part of the territory of Japan, which have never been held by foreign countries. However, the Northern Territories have been under illegal occupation by the Soviet Union, and then Russia, since the Soviet Union occupied them in 1945.

The Government of Japan has energetically been continuing negotiations with Russia based on its basic policy of resolving the issue of the attribution of the four Northern Islands and concluding a peace treaty with Russia.