TOKYO — Prime Minister Shinzo Abe of Japan made an impassioned plea on Saturday to President Vladimir V. Putin of Russia for their two countries to resolve a dispute over a group of islands that has been a sore point in their relations since the end of World War II.

During a panel discussion in the Russian city of Vladivostok, at which Mr. Abe appeared with Mr. Putin and President Park Geun-hye of South Korea, Mr. Abe called for an “end to the unnatural state of affairs that has continued these 70 years.” Because of the territorial conflict over the islands, which Soviet troops occupied after Japan surrendered in 1945, Japan and Russia never signed a formal peace treaty after the war.

The panel featuring the three leaders was part of the Eastern Economic Forum, an investment conference sponsored by the Russian government to encourage foreign companies to develop business partnerships in Russia’s far east, whose port city of Vladivostok is much closer to Seoul and Tokyo than to Moscow. All three countries have their own reasons for seeking closer economic ties with one another, including a mutual desire to find counterweights to a rising China in Asia.

Although Mr. Abe and Mr. Putin had held a bilateral meeting on Friday to discuss negotiations over the disputed islands — which Russia calls the southern Kurile Islands and Japan calls the Northern Territories — Mr. Abe took the opportunity while sharing the stage with the Russian president to address him directly.