The defense ministers of South Korea and Japan held talks in Singapore on Saturday for the first time since military relations between the two countries went sour over a radar row in December.

Japan's public broadcaster NHK reported that South Korean Defense Minister Jeong Kyeong-doo and his Japanese counterpart, Takeshi Iwaya, spoke for about 30 minutes on the sidelines of the Asia Security Summit, also known as the Shangri-La Dialogue.

The report said that the two sides agreed to work to improve bilateral ties in order to respond to North Korean issues although they have not narrowed differences on the radar lock-on incident.

Defense ties between Seoul and Tokyo have been strained since December, when Japan claimed that a South Korean destroyer directed its fire-control radar at its maritime patrol aircraft. South Korea has rejected the claim, saying the airplane needlessly approached the ship, which was on a normal rescue mission.

During the unofficial meeting, Iwaya reportedly repeated Tokyo's position in defense of the Japanese aircraft, while Jeong rebuffed Japan's allegation and called for Tokyo's measures to prevent a recurrence.

However, the defense chiefs reportedly agreed on the importance of close defense cooperation between their nations in order to maintain regional security in East Asia in relation to North Korea's firing of short-range missiles last month and agreed to improve relations of the two nations' defense authorities.