A South Korean defense ministry source has revealed that the country conducted a military drill around islands claimed by Japan earlier this month.
The source said on Friday the Navy and the Coast Guard took part in the regular drill on December 4.
The South Korean military conducts the exercise twice a year to practice preventing attempts to land on the islands in the Sea of Japan. It carried out a drill in June this year.
The defense ministry source says the latest drill did not involve a landing exercise due to the coronavirus, just like the one in June. It was even further scaled down.
South Korea controls the islands, which it calls Dokdo. Japan claims the islands. The Japanese government maintains they are an inherent part of Japan's territory. It says South Korea is illegally occupying the islands. Japan calls them Takeshima.
Japanese Chief Cabinet Secretary Kato Katsunobu said on Friday that if South Korea conducted a drill in connection with Takeshima, it is unacceptable and extremely regrettable. He stressed that the islands are clearly an inherent part of Japan's territory in light of historical facts and international law.
Kato said the government immediately lodged a strong protest with Seoul.