Japan and Russia both lay claim to the Kuril Islands, an archipelago off the north-east coast of Hokkaido. Russian President Vladimir Putin and Japanese Prime Minister Shinzo Abe held talks about the dispute last year.
Japan's Chief Cabinet Secretary Yoshihide Suga said on Wednesday, 2 September, he would seek to conclude a peace treaty with Russia if he is elected as the head of the ruling party and new prime minister.
He said he would make “every effort to push them further forward.”
So what is the dispute all about?
Four volcanic islands – Iturup (Etorofu), Kunashir (Kunashiri), Shikotan and Habomai – have been claimed by both countries since the end of the Second World War.
They are referred to as the Southern Kurils by Russia and by Japan as the Northern Territories.
The largest of the four – Iturup – is the same size as Rhode Island, the small US state but has only 7,500 residents, most of whom are fishermen, military personnel or their families.
The islands have a valuable strategic position – as they are close to shipping lanes leading to and from the port of Vladivostok – and oil was discovered off the coast of nearby Sakhalin last year.
Since President Putin's visit to Japan in December 2016 Russo-Japanese relations have been improving and there have even been plans to develop joint projects on the islands. But sovereignty remains a key issue.
In 1905, after being defeated in the Russo-Japanese War, the Tsar recognised the Kuril Islands as…