MOSCOW - Russian Prime Minister Dmitry Medvedev landed Saturday in the Kuril islands, prompting a swift rebuke from Tokyo, which has claimed sovereignty over the Pacific archipelago in a long-running dispute.
Medvedev landed on Iturup, one of four islands in the chain that lies off Russia's far eastern coast and just north of Japan, Russian media reports said.
Hajime Hayashi, the head of the Japanese foreign ministry's European division, telephoned the Russian ambassador in Tokyo over the visit to the islands, which Japan calls the Northern Territories.
The trip "contradicts Japan's position over the Northern Territories and hurts the feelings of the Japanese people... It is extremely regrettable", Hayashi said, quoted by a foreign ministry official.
Soviet troops seized the islands just after Japan surrendered in World War II, with the seven-decade dispute hampering trade and keeping Moscow and Tokyo from signing a post-war peace treaty.
Both the Kremlin and Japanese Prime Minister Shinzo Abe had hoped to start mending relations in order to revive trade, with Japan seeking broader access to Russia's plentiful oil and natural gas supplies.
Medvedev also visited the islands in 2012, and Russia held military exercises there in 2014. Both incidents provoked protests from Tokyo.
According to the Interfax news agency, Medvedev will visit a forum on the education of Russian youth and several economic projects on the archipelago, including Iturup Airport, which opened in September.