NEW : Russian Foreign Minister Sergey Lavrov denies the visit is worth a comment . Russian Prime Minister Dmitry Medvedev visits Kunashir Island , near Japan 's island of Hokkaido . That dispute has prevented the two countries from signing a formal peace treaty following World War II . Japan calls the visit `` wrong '' and says it will not be repeated in future.
NEW : Russian Foreign Minister Sergey Lavrov denies the visit is worth a comment . Russian Prime Minister Dmitry Medvedev visits Kunashir Island , near Japan 's island of Hokkaido . Japan calls the visit `` wrong '' and says it will not be repeated in future.