Putin Makes First Visit to Disputed Kuril Islands Amid Protests From Japan

President Vladimir Putin visited Russia's far-eastern Kuril Islands for the first time on Thursday, prompting protests by Japan, which also claims the territory.

Russian-Japanese relations have long been dogged by the contested islands, known in Japan as the Northern Territories and seized by the Soviet Union in 1945.

The Kremlin posted a video of Putin on one of the four main islands of the Kurils, with Russian media reporting that he visited a fish-processing plant and was given caviar.

"The Northern Territories are an inherent part of Japan's territory, both historically and under international law," Japanese Prime Minister Sanae Takaichi told reporters.

Putin's visit "offends the sentiments of the Japanese people and is absolutely unacceptable," she said, adding that it "made it more difficult to restore relations in the medium to long term."

Putin travelled to the Kurils after visiting the nearby Russian island of Sakhalin on Wednesday, where Russia's navy was conducting drills.

In Sakhalin, Putin held a meeting "on ensuring the security of Russia's eastern borders," RIA Novosti said.

In 2010, then-president Dmitry Medvedev became the first Russian leader to visit the disputed territory. Medvedev also went there several times subsequently as prime minister.