The talks that began on Wednesday on the northern side of the heavily fortified demilitarised zone (DMZ) focus on avoiding naval clashes in the Yellow Sea, west of the Korean peninsula.
In recent years, the rich fishing grounds have been the scene of naval conflicts during the crab-fishing season in May and June that have killed or wounded scores of sailors on both sides.
The two Koreas technically remain at war because the 1950-53 Korean war ended in a truce rather than a peace treaty. The DMZ that bisects the Korean peninsula separates about 1.8 million troops.
The defence ministers of the rival Koreas met once in 2000 and more junior officers have worked together successfully in the building of rail and road links through the DMZ.