South Koreawill not accept a move byJapanto internationalize the issue of a set of disputed islets claimed by both Seoul and Tokyo, according to a senior South Korean official.

The remarks, made by an unnamed diplomat in a phone call with Seoul's Yonhap News Agency on Saturday, came after the Japanese government said it is considering taking the matter to the International Court of Justice (ICJ).

South Korean President Lee Myung-bak on Friday paid a landmark visit to the lonely East Sea islets known as Dokdo here and Takeshima in Japan. The unprecedented trip, which made Lee the first South Korean president to set foot on the islets coveted for rich mineral resources in its surrounding waters, raised Tokyo's ire.

Japanese Foreign Minister Koichiro Gemba said earlier in the day that his government must respond firmly to territorial issues, adding that he will consider "measures designed to peacefully resolve disputes on the basis of international law, including submitting an application to the ICJ."

In response, the South Korean official noted that the move by the Japanese side is to "make the Dokdo issue an international dispute", adding that the basic stance of the Seoul government is that it will not accept the move "because Dokdo is clearly our territory", according to Yonhap.

Since South Korea has not accepted compulsory jurisdiction of the ICJ, the Japanese move is unrealistic because Seoul must consent before the issue can be sent to the court, the official was quoted as saying.

Both South Korea and Japan claim sovereignty over the lonely islets, lying halfway between the two countries. South Korea has controlled the islets since 1950s.