Japan Prime Minister Sanae Takaichi has criticized Russian President Vladimir Putin 's first-ever visit to the disputed Kuril Islands, saying they were "inherently Japanese territory."
In a post on X, Takaichi said Thursday that Tokyo had "repeatedly requested the Russian side to ensure that the president does not visit the Northern Territories." The Northern Territories refer to the Kuril Islands.
She added that Putin's visit was "absolutely unacceptable."
The Kuril Islands sit between the southern tip of Russia's Kamchatka Peninsula and the north-eastern corner of Japan's Hokkaido. The sparsely populated and volcanic archipelago separates the Sea of Okhotsk from the Pacific Ocean. The four southernmost islands of the chain were annexed by the Soviet Union when it launched an invasion of Japanese territory toward the end of World War II.
During his trip , Putin visited the island of Iturup, where Russia operates a strategically important military base. Russia's president toured a fish processing complex, a hospital and a school, before holding a meeting with Valery Limarenko, the regional governor of Sakhalin.
The visit was also criticized by Japanese Foreign Minister Toshimitsu Motegi, who posted on Facebook that "Japan strongly protests this visit."
Japan renounced "all right, title and claim to the Kuril Islands" in the 1951 Treaty of San Francisco but did not recognize Soviet sovereignty over the territory.
The dispute over the islands had prevented Tokyo and Moscow from signing a peace treaty since the end of the war, although a 1956 joint declaration ended the state of war between the two nations.
Analysts at the Institute for the Study of War, a Washington-based think tank, said that Putin's visit was likely part of the Kremlin's response to Japan's latest defense white paper and aims to undermine Takaichi's efforts to improve Japan's defense capabilities.
Japan published its defense white paper earlier in the month, prompting outcry from Putin, as well as Russia's ally, North Korea. Russia's president criticized the white paper for identifying Moscow as one of Tokyo's critical threats.
"Russia is continuing active military activities in the Northern Territories, which are inherent territories of Japan, under illegal occupation," the white paper said.
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