TOKYO, August 13. /TASS/. Japan expresses a "strong protest" over Russian President Vladimir Putin’s visit to the Kuril Island of Iturup, according to a statemen by the Japanese foreign ministry.

The ministry claims that all the "northern territories," as Tokyo refers to the southern part of the Kuril Islands, including Iturup, are an "ancestral [Japanese] territory from both the historical and legal standpoints."

On Thursday, Putin for the first time visited the Kuril Islands. Russian heads of state and government visited the Kuril Islands five times. Dmitry Medvedev made trips there four times: in 2010, when he was Russian president, and in 2012, 2015, and 2019, when he was prime minister. In 2021, Prime Minister Mikhail Mishustin visited Iturup.

Russia and Japan have been negotiating a post-World War II peace treaty since the mid-20th century. The main stumbling block is the issue of who owns the South Kuril Islands. After the end of World War II, all Kuril Islands were incorporated into the Soviet Union. However, Japan claimed the Iturup, Kunashir, Shikotan islands and a number of uninhabited islands of the Lesser Kuril Ridge called the Habomai Islands in Japan as its own.

In 1956, the Soviet Union and Japan signed a joint declaration on ceasing the state of war. The two countries resumed diplomatic and other relations, but have still not signed a peace treaty.

The Russian foreign ministry has repeatedly said that Russia’s sovereignty over the Kuril Islands is not up for debate, as international agreements stipulate that they belong to Russia.