Visiting Russian Foreign Minister Sergei Lavrov has offered assurances that his country will strive to resolve the long-standing territorial dispute over the four islands northeast of Hokkaido, Foreign Minister Masahiko Komura said Tuesday.

Nevertheless, the two ministers failed to make progress on the issue, which remains the thorniest issue between Japan and Russia.

Because of the dispute, the two countries have not concluded a peace treaty ending World War II.

"What is most important is to maintain the desire to resolve (the territorial issue) in addition to carrying on negotiations," Komura said after meeting with his Russian counterpart.

Lavrov told reporters that although the Russian side has agreed to take up the issue in diplomatic talks between the two countries, any solution "must be acceptable to the public and the parliaments of both countries."