The conditions are Seoul's capability 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.

"South Korea and the US will jointly assess whether those conditions are satisfied, while closely looking into security situations," Choi added.

The allies are eying 2022, or thereabouts, as a target date for the OPCON transfer, which calls for a South Korean general to command the CFC with a US general taking supportive roles, and conducted the initial operational capability test last month to check if Seoul is on course to meet the conditions.

The two sides also tentatively set the target timeframe for the relocation of the CFC headquarters to Camp Humphreys, a sprawling US military complex in the city of Pyeongtaek, south of Seoul, as 2021, with the plan to be finally approved by their defense chiefs during their planned talks later this year.

"The relocation plan will also proceed as planned," Choi said, adding that it was "decided through close discussions between the two sides after comprehensively taking into consideration related factors, including the effectiveness of operations, the CFC's working conditions, transition timing and costs."

Speaking of the proposal by the former commanders, Cheong Wa Dae spokesperson Ko Min-jung said at a press briefing that it was just "one of many opinions." (Yonhap)