South Korean PM visits disputed islets

South Korea's prime minister made a historic visit Tuesday to a group of rocky islets controlled by Seoul but claimed also by Tokyo, as his administration sought to cement its hold over them.

Han Seung-Soo, accompanied by two other cabinet ministers, arrived at the rugged, treeless terrain midway between South Korea and Japan shortly before noon, officials at his office said.

He is the highest-ranking South Korean official to visit the tiny islands, which came with Seoul feeling under mounting pressure in a territorial dispute that has flared up again with Tokyo's renewed claims.

Han met a police contingent and unveiled a monument inscribed with "Dokdo belongs to South Korean territory," his aides said.

The islands are called Dokdo by South Koreans and Takeshima in Japan.

Han told his cabinet before the trip that he wanted to "firmly make sure that Dokdo has historically belonged to South Korean territory," spokesman Song Ki-Jin said.

The previous highest-ranking official to visit was the communications minister in 2005.

Han called it "very regrettable" that the United States has re-categorised the islets, a move seen here as a diplomatic setback.

In Tokyo, Japanese foreign ministry spokesman Tomohiko Taniguchi said his government had "no official response" to Han's visit while linking it to a US federal body's decision on the islets.

"One can imagine that the action taken by the South Korean prime minister would be in response to the fact that some sort of changes have been produced by the US Board on Geographic Names," he said.

Officials said Monday that President Lee Myung-Bak was "outraged" to learn the US board had modified its classification of the islets from a territory of South Korea to one with "undesignated sovereignty."

They said Lee ordered a probe to see if Seoul's embassy in Washington and its ambassador should be held responsible for possible "negligence of duty" in handling the case.

South Korea has promised to do its "utmost" to reverse the US decision and has also confirmed plans to hold two major military exercises near the islets this year, sparking protests from Japan. The defence ministry said the first one is due Wednesday.

The navy said six ships -- including a 3,000-tonne destroyer backed up by P-3C reconnaissance aircraft and LYNX anti-submarine helicopters -- would team up with F-15Ks and two coast guard ships.

The annual military drills had been held in a low-key or closed manner before but were made public this year.

Seoul stations a small unit of maritime police in the islands and plans to make them habitable for civilians.

The dispute originates in Japan's 20th century imperial expansion and its colonisation of the Korean peninsula.

Japan claimed the islands in 1905 after winning a war with Russia. It went on to annex the entire Korean peninsula from 1910 until its defeat in 1945 at the end of World War II.

(Agencies)