Japan will take its territorial claim over Korea's Dokdo islets to the International Court of Justice later this month, the Nihon Keizai Shimbun reported on Thursday. It is a largely symbolic move since the court needs Korea's consent to become active in the case.

The Korean government has rejected Japan's proposal to present the issue jointly to the ICJ, saying there is no dispute since Dokdo belongs to Korea according to both historic records and international law.

The Japanese government nonetheless believes this is a useful way to lend international legitimacy to its flimsy claim to Korea's easternmost islets.

In order to support the claim, Japan is preparing various documents and legal precedents. Tokyo originally planned to take the issue to the ICJ next year, but brought the schedule forward to avoid clashing with the next Korean administration, which takes office in 2013.

Seoul is apparently weighing the options of either sending a written reply to the ICJ stating the reason why the islets cannot be the subject to a lawsuit, or simply ignoring the issue.