TOKYO - Japanese Prime Minister Shinzo Abe on Friday (Sept 14) again ruled out any peace treaty with Russia unless a resolution can first be reached in a territorial dispute over four islands north of Hokkaido.

It came two days after Russian President Vladimir Putin caught him off guard with a surprise comment at an economic forum in Vladivostok, that the two countries ought to sign a peace deal by year end and without any preconditions.

"Japan still maintains its stance that it will resolve territorial issues before signing a peace treaty," Mr Abe said during a debate with his rival, former defence chief Shigeru Ishiba, for a ruling party leadership election next Thursday (Sept 20). This position, he added, has been clearly communicated to Mr Putin both before and after he made the proposal.

Even so, Mr Abe added: "We must be open to the embedded message in President Putin's words. There's no denying that he has indicated his view that a peace treaty was necessary."

Japan and Russia have not signed a peace treaty in the 73 years since the end of World War II due to the disputed islands - collectively known as the Northern Territories in Japan and the Southern Kurils in Russia. They were seized by the former Soviet Union in the closing days of the war.

The two countries have agreed to conduct joint economic activities on and around the disputed islands. But progress has been slow, as they have yet to iron out the details of a special arrangement such that the projects - in five areas including tourism and aquaculture - do not compromise their respective legal sovereign claims to the islands.

Mr Abe and Mr Putin have thus far held 22 bilateral summits.

Mr Abe said on Friday that their upcoming meetings in November and December - on the sidelines of the Asia-Pacific Economic Cooperation Summit in Papua New Guinea and the Group of 20 Summit in Buenos Aires - will be important to the trust-building process.