Video. Putin watches Russian navy drills off Russia's Sakhalin Island

Footage released by Russian state television showed President Vladimir Putin aboard the missile cruiser Varyag, the flagship of the Pacific Fleet, watching live‑fire naval exercises and an underwater explosion off Russia’s Far East. He later travelled to one of the archipelago's four main islands, marking the first visit to the Kurils by a Russian president since Dmitry Medvedev went there in 2010.

Japan's Prime Minister Sanae Takaichi described the visit as "absolutely unacceptable", saying the islands were an inherent part of Japan. Foreign Minister Toshimitsu Motegi also summoned Russia's ambassador in Tokyo to lodge a formal protest, warning that the visit could further damage already strained relations.

The Kuril Islands have been disputed by Russia and Japan since 1945, when the Soviet Union seized the archipelago. Home to around 20,000 Russians, the islands are strategically important to Moscow for their military position and access to the Pacific, while the surrounding waters and nearby Sakhalin are rich in fishing, oil and gas. Putin’s visit and the naval drills reinforce Russia’s territorial claims and military presence in the region, sending a clear message to Japan and its Western allies.

Reporting from euronews contributed to this story.