The Republic of Korea on Tuesday protested Japan's renewed territorial claim over disputed islets in Tokyo's latest defense white paper, and experts said historical issues will pose a major challenge for Tokyo-Seoul ties.

The ROK summoned Kurai Takashi, Japan's deputy chief of mission in Seoul, to protest Japan's claim to the disputed islands lying nearly equidistant between the two countries, the ROK Foreign Ministry told Yonhap news.

Japan's Cabinet issued its latest annual defense white paper on Tuesday, again claiming that the islets, known as Dokdo in the ROK and Takeshima in Japan, are an integral part of Japanese territory.