The US remains "unwavering" in its recognition of Japanese sovereignty over disputed islands claimed by Russia, US Ambassador to Japan George Glass said Friday, a day after Russian President Vladimir Putin visited Iturup Island.
Washington "remains unwavering in its support of its most important ally and in its recognition of Japanese sovereignty over the Northern Territories," Glass said on US social media company X.
"At a time when the US-Japan Alliance is dedicated to cultivating prosperity across the Indo-Pacific, we strongly oppose any action that undermines its peace and stability," he added.
Glass' remarks marked the first US reaction to Putin's visit.
On Thursday, Putin visited the island, which Japan calls Etorofu, marking his first trip to the Russian-controlled, Japanese-claimed island chain off Hokkaido. Russia refers to the islands as the southern Kuril Islands.
Tokyo maintains that the Northern Territories, consisting of Iturup, Kunashiri, Shikotan and the Habomai islet group, were "illegally" seized by the now-defunct Soviet Union soon after Japan's surrender in World War II on Aug. 15, 1945.
Russia maintains that the seizure was legitimate.
The dispute has prevented the two countries from signing a peace treaty since World War II, while tensions have deepened in recent years amid Japan's sanctions against Moscow over the Russia-Ukraine war.
The Japanese government on Thursday summoned Nikolay Nozdrev, Russia's ambassador to Tokyo, to lodge a "strong protest" over Putin's visit, while Prime Minister Sanae Takaichi said the islands are an inherent part of Japanese territory "both historically and under international law."
