Photo/Illutration A navigational chart from the late Edo Period (1603-1867) shows the disputed Takeshima islets as Japanese territory. (Provided by the Japan Institute of International Affairs)

SEOUL--South Korea’s foreign ministry summoned a Japanese diplomat on Tuesday to protest a claim in Japan’s annual diplomatic policy Bluebook over a group of islands between the countries at the center of a longstanding territorial row, Yonhap news reported.

Earlier, South Korea’s foreign ministry said it “strongly protests” the claim made in the Diplomatic Bluebook issued by Japan on Tuesday and said the islands were historically and geographically its sovereign territory.

While ties between the two countries have improved recently, the neighbors are at odds over the sovereignty of the islands called Dokdo in South Korea and Takeshima in Japan that lie about halfway between them.