North Korea’s border build-up opens a Seoul-UN Command rift

The dispute follows a separate disagreement over which authority should govern access to the demilitarised zone (DMZ), while analysts say differences also persist between Seoul and Washington over the future role of US Forces Korea (USFK).

The allies are similarly misaligned on the role of the 28,500 American troops stationed on the peninsula. Seoul maintains their primary purpose is deterring a nuclear-armed Pyongyang, while Washington has increasingly sought to expand their strategic role.

The latest controversy emerged after South Korea’s military repeatedly characterised North Korea’s efforts to fortify areas near the military demarcation line (MDL) as a “clear violation” of the armistice agreement.

On Tuesday, the UNC released a detailed fact sheet reaffirming its position that Pyongyang’s activities did not breach the agreement. The construction projects in question, including fence installation, road repairs and minelaying operations, had all been carried out on the northern side of the MDL, the command said.