Defense Minister Han Min-koo and his Japanese counterpart will hold a telephone conference Friday to discuss ways to jointly react to North Korea's recent nuclear test, government officials said.

Han plans to have phone talks with Japanese Defense Minister Gen Nakatani at 9:30 p.m. over how to coordinate against North Korea's nuclear threats, according to the Defense Ministry.

The North claimed Wednesday that it successfully conducted a hydrogen bomb test for the first time, posing a threat to security in Northeast Asia.

The action taken by the defense chiefs of Seoul and Tokyo is seen as an sign that they are speeding up military cooperation in the face of the North's fourth nuclear test.

The two countries' military cooperation has been stagnant as their relations have been frayed over a row over Japan's wartime sexual enslavement of Korean women.

The bilateral military cooperation is part of efforts by South Korea, the United States and Japan to strengthen their trilateral cooperation against the North's evolving nuclear threats.

Earlier in the day, ranking defense ministry officials between the three nations held a video conference to share information over the North's nuclear provocation and discuss how to cope with it. (Yonhap)