Japan and Russia are exploring the idea of conducting cruises around the Moscow-held, Tokyo-claimed islands off Hokkaido as part of envisioned economic collaboration, a diplomatic source said.

The countries will hold a vice foreign ministerial meeting Thursday in Moscow to discuss possible joint projects before the nations' leaders meet in Vladivostok in early September.

Prime Minister Shinzo Abe and Russian President Vladimir Putin agreed in December 2016 to collaborate on economic projects on the islands. Japan hopes the efforts pave the way toward settling the decades-old territorial dispute, while Russia hopes to attract Japanese investment.

However, as the two sides remain far apart in their stances on sovereignty over the islands, they would need to work out how to conduct joint projects in a way that does not raise judicial problems.

A group of Japanese government officials and experts from the public and private sectors visited the islands in late June to study possible areas of cooperation, including tourism.

"I saw its potential as a tourism resource," Eiichi Hasegawa, a special adviser to Abe, told reporters at the time.

The disputed islands have an ecosystem similar to the neighboring Shiretoko Peninsula of Hokkaido, a scenic UNESCO World Natural Heritage site.

The islands of Etorofu, Kunashiri, Shikotan and the Habomai islet group were seized by the Soviet Union after Japan surrendered in August 1945, ending World War II.

The territorial dispute has prevented the two countries from signing a postwar peace treaty.