MOSCOW • A string of desolate volcanic islands are at the heart of a feud between the two countries that dates back to World War II.
As Russian President Vladimir Putin holds talks in Japan with Prime Minister Shinzo Abe over the territorial dispute, here are some key facts on the islands, known as the Southern Kurils by Russia and the Northern Territories by Japan:
• The disputed islands of Iturup (Etorofu in Japanese), Kunashir (Kunashiri), Shikotan and Habomai at their closest point lie just a few kilometres off the north coast of Hokkaido.
• They are located to the south-east of Russia's Sakhalin island and are administratively part of the same region, although Tokyo considers them part of Hokkaido prefecture and "illegally occupied by Russia".
• Russian Empress Catherine the Great claimed sovereignty over the Kuril islands in 1786 after her government declared they were discovered by "Russian explorers" and "undoubtedly must belong to Russia".
• In the first treaty between czarist Russia and Japan in 1855, the frontier between the two countries was drawn just north of the four islands closest to Japan.
• In 1875, a new treaty handed Tokyo the entire chain, in exchange for Russia gaining full control of Sakhalin.
• Japan seized control of Sakhalin's southern half after it defeated Moscow in the 1905 Russo-Japanese War.
• The Kuril islands returned to the centre of a dispute between Moscow and Tokyo when Soviet troops invaded them in the final days of World War II.
• Russia argues that it was promised the Kurils at the Yalta conference in February 1945, when Allied leaders divided up the post-war world, in exchange for joining the war against Japan.
• The Soviet capture of the islands has prevented Moscow and Tokyo from signing a formal peace treaty to end the war, despite repeated attempts over the past 70 years.