Japan protests Putin visit to disputed Kuril Islands

Japan on Thursday strongly protested Russian President Vladimir Putin's visit to Iturup, one of four southern Kuril Islands claimed by both Russia and Japan, in his first reported visit to the disputed island chain.

Japanese Foreign Minister Toshimitsu Motegi said the islands were "inherently Japanese territory both historically and under international law" and that Tokyo "strongly protests" Putin's visit.

Iturup, known as Etorofu in Japan, is administered by Russia but is among the four islands that Japan refers to as the Northern Territories. The dispute has remained a major source of tension between the two countries for decades and is the principal reason Moscow and Tokyo have never signed a formal peace treaty following World War II.

Putin visited a fish-processing facility on Iturup, sampled local fish roe and met residents during his trip, according to Russian state media. He also toured other facilities on the island, including a hospital and school, and met Sakhalin regional governor Valery Limarenko.

The Kuril Islands stretch between Japan's northern island of Hokkaido and Russia's Kamchatka Peninsula. The four southernmost islands — Iturup, Kunashir, Shikotan and the Habomai Islands — are administered by Russia but claimed by Japan.

The Soviet Union seized the islands at the end of World War II in 1945 and Japanese residents were subsequently deported. Japan has maintained its territorial claim over the four islands, while Russia considers them part of its territory.

The territorial dispute has repeatedly complicated efforts to improve bilateral relations. Japan has protested previous visits to the islands by senior Russian officials, including former Prime Minister Dmitry Medvedev and former Prime Minister Mikhail Mishustin.

Relations have deteriorated further since Russia's invasion of Ukraine in 2022, after which Japan joined Western countries in imposing sanctions on Moscow.

The islands also have considerable strategic importance for Russia. Moscow has strengthened its military presence in the region over the past decade, including deploying military infrastructure on the southern Kurils. Iturup is home to a Russian military air base.

Putin's visit also comes amid heightened military activity in the wider region. Russian naval forces recently conducted exercises in the Far East, while Russian and Chinese warships have previously conducted joint patrols through waters around the Kuril chain.

The latest visit is therefore likely to further complicate already strained relations between Moscow and Tokyo, with Japan continuing to press its claim to the four islands while Russia maintains administrative and military control over them.