The planned joint exercise is meant to verify Seoul's capabilities for the envisioned transfer of the wartime operational control of its troops. "Preparations are under way regarding the matter," defense ministry spokesperson Choi Hyun-soo told a regular briefing.

Asked about a detailed schedule, the official said that the ministry will announce details later "at an appropriate time."

The allies have planned to hold the command post exercise around Aug., replacing the summertime Ulchi Freedom Guardian drill as part of a reorganization of major exercises aimed at supporting peace efforts with North Korea.

In response to North Korea's threats, the US said on Wednesday that the exercise program was already adjusted in cooperation with South Korea in order to maintain their readiness posture and to support diplomacy with the North.

Officials have said this year's exercise will focus on testing Seoul's initial operational capability in an initial step to verify whether Seoul is on course to meet the conditions required for the envisioned OPCON transfer from Washington to Seoul.

The two sides have agreed on a "conditions-based" OPCON transition. The conditions are the South's capabilities to lead the allies' combined defense mechanism; its capacity for initial responses to the North's nuclear and missile threats; and a stable security environment on the peninsula and in the region.

The allies first launched the Dong Maeng exercise in March to replace their springtime Key Resolve and Foal Eagle exercises. "Dong Maeng" means "alliance" in English.

North Korea has long demanded that Seoul and Washington stop joint military exercises, calling them rehearsals for invasion. But the allies have said the drills are defensive in nature. (Yonhap)