NAGATO, Japan - Japan and Russia on Thursday hunkered down to try and make progress towards a peace treaty formally ending World War II hostilities hamstrung by a decades-old territorial dispute.

Prime Minister Shinzo Abe is hosting President Vladimir Putin at a hot spring summit in his ancestral city of Nagato in the hopes of achieving a breakthrough.

The Soviet Union seized islands off Japan’s northern coast in 1945 in the closing days of the war. Known as the Southern Kurils in Russia and the Northern Territories in Japan, they have been a thorn in relations ever since. But Abe would like to seal a deal as soon as possible because the islands’ ageing Japanese former residents are dwindling in number.

Abe said that he and Putin spoke for three hours on a range of issues, with about half of that centred on the peace treaty.

“I think we were able to carry out frank and very straight discussions,” Abe told reporters, describing a “good atmosphere” for the summit.

Putin, at the start of the talks, said he expected they would help improve relations. “I think the summit today and tomorrow will bring a big contribution to the development of ties,” he said.

Putin, a practitioner of the Japanese martial art of judo, is making his first visit to Japan as president in 11 years and has said he wants to end the “anachronism” of the two countries not having a World War II peace treaty.

“But how to do this is a difficult question,” he told Japanese media before his arrival, damping down expectations of major progress.

Underscoring the intense interest in the meeting in Japan, Putin’s arrival at the airport in the city of Ube, about three hours later than originally anticipated, was shown live on television.

The summit is the latest attempt to draw a line under World War II since Japan and the Soviet Union began discussions in 1956.

Abe’s late father Shintaro took the lead in negotiations with Moscow as a foreign minister but died in 1991 after pushing for talks while suffering from cancer.

Japan has been careful to avoid criticising Russia, particularly its role in Syria that has drawn condemnation by Western countries, as it seeks to resolve the territorial dispute. But in what appeared to be a gentle rebuke, Abe mentioned “the importance of Russia playing a constructive role in international issues”.

Abe has looked to eke out concessions by dangling the prospect of major Japanese investment in front of Moscow, which is mired in economic crisis.

He said they also discussed joint economic development of the islands and making it easier for Japanese former residents, whose average age is 81, to visit.

“I held talks, keeping in mind that the former islanders feel that they have no time to spare,” Abe said, mentioning that he handed Putin letters from some of them.

Yuri Ushakov, a Kremlin advisor, told reporters that the two leaders called for experts to find ways to achieve joint exploitation of the territory, citing “fishing, tourism, culture and medicine”.

But few believe Putin is likely to cave to Japanese demands to hand back at least some control over the islands, especially after Donald Trump’s election as president of the United States last month.

The New York real-estate baron has vowed to improve ties with Russia, where the economy has reeled under US sanctions against Moscow over Ukraine and the impact of falling oil prices. Abe and Putin will hold further talks in Tokyo on Friday.