Japan's prime minister Shinzo Abe has said summit talks with Russian president Vladimir Putin must take place in order for the countries to forge a peace treaty.

Japan and Russia never signed a peace treaty after the Second World War because of territorial disputes over islands north of the Japanese island of Hokkaido, which Japan calls its "Northern Territories".

When asked about Mr Putin in a news conference, Mr Abe said, "We both recognise that 70 years after the war's end, to not have concluded a peace treaty is abnormal. But without a summit meeting this Northern Territories problem cannot be resolved."

He also said it was crucial that Russia played a constructive role in fighting terrorism and in the crises in Iran and Syria.

Since taking office in late 2012, Mr Abe has sought to make progress on improved relations with Russia, but the conflict in Ukraine and other issues have complicated that effort.

Several tentative plans for a visit by Mr Putin to Japan have been put off over western concerns about Russia's involvement in such crises.

Mr Abe also said Japan's often tense relations with China and South Korea were "normalising", following a summit in Seoul and he hoped for further progress.