Japan has strongly protested Russian President Vladimir Putin’s first-ever visit to the disputed Kuril Islands, with Prime Minister Sanae Takaichi calling the trip “absolutely unacceptable” and saying it had worsened Japanese sentiment toward Russia.
Putin visited Iturup, known in Japan as Etorofu, on Thursday, as the decades-old territorial dispute between Moscow and Tokyo remains unresolved.
Russian state media reported that Putin met the regional governor and visited a fish-processing plant, hospital and school on Iturup, the southernmost of four Russian-administered islands claimed by Japan.
Takaichi said the visit was incompatible with Japan’s consistent position on what Tokyo calls the Northern Territories and urged Russia to take the matter seriously.
Foreign Minister Toshimitsu Motegi said the islands were inherently Japanese territory historically and under international law, and Japan’s Foreign Ministry summoned the Russian ambassador to lodge a strong protest.
The four disputed islands were seized by the Soviet Union in 1945, after which about 17,000 Japanese residents were deported.
The territorial dispute has prevented Russia and Japan from signing a peace treaty formally resolving their World War Two hostilities.
Putin travelled to the Kurils after visiting nearby Sakhalin on Wednesday, where Russia’s navy was conducting drills and he held a meeting on security along Russia’s eastern borders.
He also criticised Japan’s sanctions against Russia as unprovoked and said Moscow was not threatening Japan, while pointing to Tokyo’s territorial claims.
Relations have deteriorated further since the conflict in Ukraine began in 2022, when Japan joined other G7 countries in imposing sanctions on Russia and provided money and non-lethal defence assistance to Kyiv.
Russia has strengthened its military presence on the Kurils over the past decade, with Iturup serving as its primary military air base in the region.
Last month, Russian and Chinese naval warships also sailed through a strait in the Kuril Islands during a joint patrol.
Japan has repeatedly protested Russian military activity and previous visits by senior Russian officials to the disputed territory.