Foreign Minister Taro Aso said Thursday that he and his Russian counterpart, Sergei Lavrov, agreed to push forward strategic relations and to continue negotiations to resolve a long-standing territorial dispute.

Aso also announced that Prime Minister Shinzo Abe and Russian President Vladimir Putin will hold talks on the sidelines of the Group of Eight summit in Heiligendamm, Germany, in June.

"On the territorial dispute, we agreed to continue negotiating vigorously to seek a mutually acceptable resolution based on the various agreements and documents we have had so far," he told reporters after the two-hour meeting with Lavrov, which included a working lunch.

To lay the groundwork for the Abe-Putin summit, Japan and Russia agreed to hold a vice-ministerial meeting in Moscow on May 17 and strategic dialogue talks in Tokyo on May 29, Aso said.

Two ministers also exchanged views on the North Korean and Iranian nuclear threats, as well as Middle East situation, Aso said.

They also discussed disaster prevention and environmental protection in and around the Russian-held disputed islands off Hokkaido, Aso said.