Russian Prime Minister Dmitry Medvedev on Tuesday visited Kunashiri Island, one of four islands known collectively as the Northern Territories whose sovereignty is disputed by Japan and Russia.

He first tried to land on Etorofu Island, another disputed island, but could not do so because of thick fog. In November 2010, Mr. Medvedev, then president, visited Kunashiri becoming the first Russian head of state to visit the Northern Territories.

Mr. Medvedev's visit to Kunashiri runs counter to an agreement between Japanese Prime Minister Yoshihiko Noda and Russian President Vladimir Putin on June 18 during the Group of 20 summit in Los Cabos, Mexico, that Japan and Russian will "reactivate talks" on the long-standing territorial dispute in a quiet atmosphere.