Dokdo, which lies closer to South Korea in the East Sea between the Korean Peninsula and Japan, has long been a source of tension between the neighbors. South Korea has kept a small police detachment on the islets since 1954 and has made clear that Tokyo's claims are groundless.

South Korea immediately voiced its protest with Japan's renewed claim on Dokdo.

Shortly after the release of the white paper, the defense ministry urged Japan "not to repeat such an act" and warned that it would take "stern" measures against any attempt to hurt the country's sovereignty of the islets.

The ministry called in a defense attache from the Japanese Embassy in Seoul to lodge a formal protest with Tokyo.

The foreign ministry also issued a statement in which it made it clear that Dokdo is South Korean territory and expressed its strong protest with Japan's "unjust" claim on the islets.

"The Japanese government should stop making such a useless claim on Dokdo immediately, see squarely historical facts and actively work in a way that South Korea-Japan ties can move toward the future based on mutual trust," it added.

Japan's renewed claim on Dokdo is likely to adversely affect relations between South Korea and Japan which had been showing signs of improving after the two sides reached a deal last year to resolve the long-running rift over the sexual slavery of Korean women who were sent to Japanese military brothels during its colonial rule of the peninsula.

In his bilateral talks with South Korea's Foreign Minister Yun Byung-se, which was held on the sidelines of a regional security forum in Laos last week, Japanese Foreign Minister Fumio Kishida expressed that he was pleased with the improving ties with South Korea, after the landmark deal was reached on Dec. 28. (Yonhap)