The Japanese government has lodged a protest against Russia after Moscow said it is holding target practice in waters near a Russian-held island claimed by Japan off the northern main island of Hokkaido, the top government spokesman said Thursday.

Chief Cabinet Secretary Katsunobu Kato said Russian authorities issued Saturday a navigation warning covering four days from Thursday as well as Sept. 13-17 over the exercise in what Kato called Japanese waters off Etorofu Island.

Japanese Chief Cabinet Secretary Katsunobu Kato speaks at a press conference in Tokyo on Aug. 23, 2021. (Kyodo)

"We lodged a protest saying it is not acceptable," Kato said at a regular press conference.

Kato added the long-standing territorial dispute over what Tokyo refers to as the Northern Territories, comprising four islands, "needs to be fundamentally resolved" and that Japan will pursue negotiations with Moscow "tenaciously."

The row over the islands, known as the Southern Kurils in Russia, has prevented the two countries from concluding a postwar peace treaty. Russia wants Japan to recognize that the four islands were legitimately acquired following Tokyo's surrender in World War II, while Japan takes the view that the seizure was illegal.

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