Yuri Ushakov, foreign affairs adviser to Russian President Vladimir Putin, said Friday that the president will hold a meeting with Prime Minister Shinzo Abe in Moscow on May 26, Russia’s Interfax news agency reported.

The Japanese and Russian governments are aiming to reach an agreement on launching joint economic activities on and around the Russian-controlled islands off Hokkaido that are at the center of a decades-old territorial dispute.

In a related move Friday, high-ranking Japanese and Russian officials held detailed talks in Moscow on five areas for the joint activities, including tourism and aquaculture.

Participants included Deputy Foreign Minister Takeo Mori and his Russian counterpart Igor Morgulov.

Also present was Eiichi Hasegawa, a special adviser to Abe. Hasegawa headed a public-private delegation that visited some of the four disputed isles last year for research related to the joint activities.

After the meeting, Mori told reporters that the participants discussed the progress they’ve made and how to proceed.

“We hope to actively make preparations so that we can continue moving ahead for our common goal of concluding a peace treaty,” he added.

The four isles in question were seized by the former Soviet Union from Japan at the end of World War II. Russia’s refusal to give them back has prevented the two countries from signing a peace treaty to formally end the war.

Abe is also slated to attend an international economic forum in St. Petersburg on May 25.