Defense Minister Suh Wook held phone talks with his US counterpart Lloyd Austin on Friday and reaffirmed their commitment to a strong alliance and a firm combined defense posture, the defense ministry said.

The two ministers discussed bilateral defense issues and the security situation on the Korean Peninsula, "reaffirmed an ironclad South Korea-US alliance and stressed the importance of close cooperation between the two countries," according to the ministry.

Their annual summertime military exercise is also expected to have been an agenda item amid concern that it could negatively affect a conciliatory mood created in the wake of the restoration of inter-Korean communication lines this week.

Earlier in the day, North Korea reported that its leader Kim Jong-un has accused "hostile forces" of intensifying "frantic and persistent war drills for aggression."

Pyongyang has long bristled at such combined drills, branding them as a rehearsal for invasion.

South Korea and the U.S. usually hold the summertime exercise in August, but the ministry has said it is still discussing with Washington when and how to stage the drills.

"The two sides agreed that maintaining a firm combined defense posture and continued communications are important to ensure the South Korea-US alliance as the linchpin of peace and security of the Korean Peninsula and the Indo-Pacific region," the ministry said in a release. 

Friday's talks took place at the request of Austin who is on a swing to Southeast Asia.

Suh and Austin agreed to continue cooperation for fruitful achievements at an upcoming Security Consultative Meeting, an annual defense ministers talks between the two countries, scheduled to take place in Seoul later this year, the ministry said. (Yonhap)