ANKARA

South Korea strongly protested Tuesday after Japan reiterated its territorial claims to disputed islets lying halfway between the two countries in this year's defense white paper, Yonhap News Agency reported.

The islets are called Dokdo by South Korea and Takeshima by Japan.

"The government strongly protests Japan's reiteration of its unjust territorial claim to Dokdo," South Korea's Foreign Ministry spokesperson said in a statement.

Describing the islets as South Korean territory in terms of "history, geography and international law," the spokesperson called for the immediate withdrawal of Japan’s claim.

The spokesperson warned that the government will respond sternly to any "provocations" from Japan regarding Dokdo.

The ministry also plans to summon an official from the Japanese embassy in Seoul later in the day to lodge a formal protest.

Earlier in the day, the Japanese government released its annual defense white paper, referring to Dokdo by the Japanese name Takeshima and describing it as part of Japan's territory.

Dokdo has long been a thorny issue between the two countries as Japan continues to make the sovereignty claims in its policy papers, public statements and school textbooks.

South Korea maintains a small police unit on the islets, effectively controlling them.