South Korean opposition Democratic Party leader Kim Han Gill on Tuesday traveled to a pair of islands in the Sea of Japan that are controlled by South Korea but claimed by Japan, triggering a protest from Tokyo.
Following the visit, which was apparently to assert Seoul's claim to the islands, Makita Shimokawa, deputy director general of the Japanese Foreign Ministry's Asian and Oceanian Affairs Bureau, summoned a South Korean diplomat to the ministry in Tokyo.
Shimokawa told Kim Won Jin, minister at the South Korean Embassy in Tokyo, that the visit was "extremely regrettable" and "unacceptable in light of Japan's territorial claim" and urged Seoul to prevent a recurrence, a Japanese government official said.
Kim asserted South Korea's right to the islands, the official said.
According to the ministry, the Japanese Embassy in South Korea, acting on a news report on a planned visit to the islands, had asked the South Korean side Monday not to allow it.
Kim, accompanied by around 10 other lawmakers and aides, arrived on the disputed islets, known in South Korea as Dokdo and Takeshima in Japan, by helicopter from a city on the east coast around 2:30 p.m., the party said in a statement posted on its homepage.
"Dokdo is our territory that should be defended any time," the statement said.
Lawmakers of the ruling Saenuri Party are reportedly planning to travel to the islets Thursday on the occasion of National Liberation Day, which marks the end of Japan's 35-year colonial rule of the Korean Peninsula in 1945.
Relations between Japan and South Korea have been strained due to the dispute over the islands, especially since August last year when then President Lee Myung Bak visited the islets, becoming the first South Korean head of state to do so.
