TOKYO: Japan has protested to Russia against its geological survey in waters including around four Russian-controlled islands that Japan calls the Northern Territories, Chief Cabinet Secretary Yoshihide Suga said Friday.

The Russian survey is "unacceptable as it conflicts with our country's position" on the islands, Suga told a press conference.

According to the Japanese Foreign Ministry, Russian authorities notified the Japan Coast Guard on June 17 of a plan to conduct the survey in the Sea of Okhotsk between June 18 and September 18.

The ministry lodged a protest with Russia within the day of notification, urging it to cancel the survey plan.

At the press conference, Suga stressed that the government is "always closely watching the Russian side's developments related to the Northern Territories."

He also said the government hopes to proceed with its negotiations with Russia under the basic policy of resolving the territorial issue and concluding a bilateral peace treaty.

JIJI Press