Japan's Abe says wants to resolve peace treaty issue with Russia

"A peace treaty between Japan and Russia has not been concluded yet, even after 70 years have passed since the end of World War Two," Abe told reporters in London. "It is an extremely unusual situation. Infinite possibilities are latent in the cooperation between Japan and Russia."

Russia and Japan did not sign a formal peace treaty at the end of World War Two because of a dispute over islands in the Western Pacific, called the Northern Territories in Japan and the Southern Kuriles in Russia.

The islands were seized by Soviet forces at the end of World War Two and 17,000 Japanese residents were forced to flee.

"Russia's constructive engagement is essential in resolving global challenges," Abe said. "It is my intention to continue to have dialogue with President [Vladimir] Putin, so as to co-ordinate regarding these challenges."