South Korea on Tuesday protested Japan's repeated sovereignty claim to the Dokdo islets in the East Sea in its annual defense white paper.

"The government strongly protests Japan's illegitimate territorial claim to Dokdo in its defense white paper and calls for an immediate withdrawal," the Ministry of Foreign Affairs said in a statement.

"The Japanese government should be aware clearly that the repeat of the claim does not help with the development of a forward-looking and mature partnership between South Korea and Japan at all," according to the statement. "We make it very clear once again that we will deal sternly with any provocations about Dokdo."

Seoul's defense ministry summoned Kyosuke Tsushima, Japan's defense attache here, to lodge a formal complaint, as this year's document was reported to Japan's Cabinet. 

The foreign ministry also called in Koichi Mizushima, minister at the Japanese Embassy in Seoul, later in the afternoon.

Earlier in the day, Japan announced the publication of its defense white paper for 2017 in which they said Dokdo is part of Japanese territory. It marks the 13th straight year Japan has laid claim to the rocky islets lying between the neighbors in their annual defense paper.

Seoul's defense ministry stressed the military will respond resolutely to attempts to undermine the country's effective control of the easternmost islets belonging to Korea "historically, geographically and by international law."

"The Japanese government must immediately stop such a pointless claim to Dokdo and face up to the history," the ministry said in a statement.

It urged Tokyo to make efforts for a "forward-looking, mature and cooperative" partnership between the neighboring countries.

Japan's assertion of its Dokdo ownership is a legacy of its imperialistic past.

Japan has laid claim to the islets in the waters between the two sides since 2005 in the white paper summarizing its defense policy direction.

As for North Korea, the defense paper assessed its nuclear and missile program as "a new level of threats," compared with the 2016 version's "grave and urgent threats."

North Korea's nuclear weapons program is making progress, the defense paper also said, adding that North Korea is launching missiles with an unprecedented frequency as it seemingly attempts to make it difficult for others to detect signs of their launch. (Yonhap)