North Korea has resumed work to reinforce its border along the Military Demarcation Line (MDL) within the demilitarized zone (DMZ), after a monthslong pause for training, South Korea’s military said Friday.

According to the ROK Joint Chiefs of Staff (JCS), Pyongyang restarted the work in early March after halting the activities in December due to winter training exercises. 

JCS said North Korean troops resumed operations in areas “just north of the MDL” and that South Korea is “maintaining a firm readiness posture while managing the situation in a stable manner.”

A “large number” of North Korean troops have also been