Japan has lodged a strong protest against Russian President Vladimir Putin's visit to the Kuril islands, a territory claimed by both nations. The Russian state media reported on Thursday that Putin visited the islands, which Japan asserts are its historical and legal territory.

In a statement, Japan's foreign minister, Toshimitsu Motegi, declared the islands "inherently Japanese territory both historically and under international law, and the Government of Japan strongly protests this visit." The islands have been the subject of a decades-long dispute between Russia and Japan.

This territorial disagreement has prevented Moscow and Tokyo from formally signing a peace treaty following World War II. The specific island visited by Putin on Thursday is known as Iturup in Russia and Etorofu in Japan. According to state media, this marks the first time the Russian leader has visited the Kuril islands.