Russia and Japan have been unable to sign a peace treaty that would formally end hostilities because of a dispute over four islands in the Kuril chain, which the Soviet Union claimed at the end of the war.
Sergei Prikhodko said Russian President Vladimir Putin and Japanese Prime Minister Junichiro Koizumi had discussed a peace treaty during a bilateral meeting in St. Petersburg during the current summit of the Group of Eight industrialized nations.
"It was stated that differences in the sides' approaches must not be an obstacle to improving bilateral cooperation," he said.
Prikhodko said the leaders had also discussed cooperation in dealing with natural disasters and visa facilitation as a step toward better humanitarian ties and developing student exchange programs.
Last month Putin told a news conference at the Russian Foreign Ministry: "In relations with Japan, the line toward continuing political dialogue and boosting economic cooperation is completely justified while maintaining a principled approach toward a peace treaty and a sincere desire to see it concluded."
The leaders of Russia, the United States, the United Kingdom, Italy, France, Germany, Canada and Japan will wrap up their three-day summit Monday.
