Korea is to reduce the number of soldiers on active duty by 110,000 by 2022.
The Defense Ministry said Thursday it plans to cut 40,000 troops over the next five years from the current 633,000 and 70,000 more between 2019 and 2022.
To fill the gap, the number of reserve soldiers will increase from the current 30 percent to 43 percent by 2025. To better prepare for the handover of full troop control currently scheduled for 2015, the military plans to merge two of its three Army headquarters and set up a ground operations command.
The initial merger date was set for 2030, but that has now been brought forward to 2026.
Experts say all the changes are being made in consideration of the nation's low birthrate as the military attempts to transition into a more efficient and cheaper force.
The military estimates that it will cost over US$201 billion over the next five years to implement the plan, which represents an average annual increase of 7.2 percent of the defense budget.