[COVER STORY] North Korea's border fortification raises questions over DMZ buffer role

North Korea’s border fortification along the Military Demarcation Line is raising questions about whether the DMZ’s buffer role is being reduced. South Korean officials say the work has continued since 2024, with minefields, fences and barriers spread close to the MDL. The South has reported repeated North Korean crossings during construction, while officials are proposing talks to clarify the boundary.

North Korea began clearing land, laying mines and building fences, barriers and tactical roads along the MDL in 2024 after Kim Jong-un defined inter-Korean relations as those between two hostile states.

The South Korean military expects the project to be completed around 2028, and as of August land-clearing work was about 90 percent complete.

A defense ministry official said only about 250 of the original 1,292 MDL markers remain along the 248-kilometer boundary.

The Defense Intelligence Agency assessed that North Korean troops crossed the MDL about 20 times in August and about 30 times in September.

Unification Minister Chung Dong-young proposed talks with North Korea on Friday to reconfirm and clearly establish the MDL.

Published Oct 3, 2026 7:00 am KST

Updated Oct 3, 2026 10:38 am KST

Minefields, barriers and unclear MDL raise risks of accidental clashes

North Korean troops lay mines in the Demilitarized Zone along the central front, June 18, 2024. The Joint Chiefs of Staff (JCS) said dozens of North Korean soldiers working in the area crossed the Military Demarcation Line before retreating after South Korean troops issued warning broadcasts and fired warning shots. Courtesy of JCS

North Korea’s continued construction of minefields, fences and barriers along the Military Demarcation Line (MDL) is raising questions over whether its border fortification campaign is changing the role of the Demilitarized Zone (DMZ), which has served as a military buffer between the two Koreas since the 1953 Korean Armistice Agreement.

The risks are becoming more apparent as North Korea builds fortifications close to the MDL in areas where Seoul, Pyongyang and the United Nations Command (UNC) do not always agree on the exact location of the line.

North Korean troops have repeatedly crossed the MDL during construction work, prompting warning broadcasts and warning shots from the South Korean military.

North Korea began clearing land, laying mines and building fences, barriers and tactical roads along the MDL in 2024, after leader Kim Jong-un defined inter-Korean relations as those between “two hostile states.”

The South Korean military expects the project to be completed around 2028. As of August, land-clearing work was about 90 percent complete, while construction of fences and minefields was estimated to be 30 to 60 percent complete, depending on the area.

Yoo Ji-hoon, a research fellow at the Korea Institute for Defense Analyses, said the fortification campaign could change the military character of the DMZ even if its formal boundaries remain unchanged.

“If North Korea places military facilities such as fences, minefields and tactical roads excessively close to the MDL, the practical military buffer space could effectively shrink even if the physical width of the DMZ itself remains unchanged,” Yoo said.

Shin Jong-woo, secretary-general of the Korea Defense and Security Forum, noted that the DMZ, which extends 2 kilometers on each side of the MDL, has served as a buffer to prevent clashes, but the North’s construction of tactical roads, fences, barriers and minefields inside could weaken that function.

“North Korea’s so-called border fortification work is ongoing,” a Joint Chiefs of Staff (JCS) official said Friday.

Defense Minister Kang Shin-chul has linked a recent mine explosion in the DMZ to the fortification work. Speaking at the National Assembly on Tuesday, Kang said a North Korean mine found near the blast site appeared to have been planted rather than washed into the area, adding that it was believed to have been laid “in connection with the border fortification.”

Unification Minister Chung Dong-young answers questions from reporters as he arrives at Government Complex Seoul, Friday, after cutting short a trip to Europe following a North Korean mine explosion in the Demilitarized Zone. Yonhap

The DMZ, however, was already heavily mined long before North Korea began its latest fortification campaign. According to JCS data submitted to the National Assembly in 2020, an estimated 380,000 mines were buried within the DMZ, part of some 828,000 mines estimated to remain across South Korea, including locations near the Civilian Control Line and rear areas.

The figures were estimates as of 2020 and do not represent the exact number of mines currently remaining.

South Korean forces also laid mines after the armistice agreement was signed to prevent North Korean infiltration and protect key military facilities. But a JCS official told The Korea Times that South Korea has not carried out new mine-laying or similar fortification work in the DMZ in response to the North’s latest campaign, distinguishing the current situation from minefields laid decades ago.

One complication is that the MDL is no longer clearly marked across much of its 248-kilometer-boundary.

A total of 1,292 markers were originally installed to identify the MDL after the armistice agreement was signed. The defense ministry confirmed Friday that only about 250 remain. South Korea and the UNC have developed their own reference lines based on armistice maps, surviving markers and terrain, but their assessments do not match in some areas.

North Korea, meanwhile, refers to the boundary as its “border.” Kim Yo-jong, the powerful sister of the North Korean leader, denied that North Korean troops had crossed it.

“Our soldiers have never crossed the border even once,” she said Tuesday. Pyongyang has not publicly specified exactly where it considers that border to be.

According to the Defense Intelligence Agency, North Korean troops were assessed to have crossed the MDL about 20 times in August and about 30 times in September.

A JCS official said North Korean troops have sometimes returned with maps and binoculars after receiving South Korean warnings and checked their location before resuming work. In some cases, they moved their work site.

Those risks became apparent on Sept. 21, when a mine explosion in the western DMZ injured three South Korean soldiers. A subsequent investigation found an additional North Korean anti-personnel mine south of the MDL, which the UNC determined constituted an armistice agreement violation.

The South Korean military is also strengthening surveillance in areas where terrain limits visibility. “Additional surveillance equipment is being installed or planned,” a JCS official said, declining to disclose locations for operational security reasons.

Unification Minister Chung Dong-young on Friday proposed talks with North Korea to clarify the MDL.

“We need to meet and communicate,” Chung said. “At the very least, we should begin talks to reconfirm and clearly establish the MDL.”

A defense ministry official said Seoul has “consistently acknowledged differences in how the MDL is understood and the need for consultations,” noting continuing discussions with the UNC.

朝鲜沿军事分界线修建边境防御工事，引发了人们对非军事区缓冲作用是否正在减弱的质疑。韩国官员表示，自2024年以来，朝鲜一直在军事分界线附近修建地雷、围栏和障碍物。韩国方面报告称，在朝鲜修建工事期间，多次发生朝鲜人员越境事件，而韩国官员则提议通过对话来明确边界。

2024年，金正恩将朝韩关系定义为两个敌对国家之间的关系后，朝鲜开始沿着军事分界线清理土地、埋设地雷、修建围栏、障碍物和战术道路。

韩国军方预计该项目将于 2028 年左右完工，截至 8 月，土地清理工作已完成约 90%。

国防部官员表示，在248公里长的边界线上，最初的1292个MDL标志只剩下大约250个。

美国国防情报局评估，朝鲜军队在8月份越过军事分界线约20次，9月份越过军事分界线约30次。

统一部长官郑东荣周五提议与朝鲜举行会谈，以重申并明确确立军事差异界限。

发布于2026年10月3日 上午7:00（韩国标准时间）

更新于2026年10月3日上午10:38（韩国标准时间）

雷区、障碍物和不明确的界线增加了意外冲突的风险。

2024年6月18日，朝鲜军队在中部战线非军事区布雷。韩国联合参谋本部（JCS）称，数十名在该地区作业的朝鲜士兵越过军事分界线，在韩国军队发出警告广播并鸣枪示警后撤退。图片由联合参谋本部提供。

朝鲜持续沿着军事分界线（MDL）修建雷区、围栏和障碍物，引发了人们对其边境防御行动是否正在改变非军事区（DMZ）作用的质疑。自1953年《朝鲜停战协定》以来，非军事区一直作为朝韩之间的军事缓冲区。

随着朝鲜在靠近军事分界线（MDL）的地区修建防御工事，风险变得越来越明显，因为首尔、平壤和联合国军司令部（UNC）对这条线的确切位置并不总是达成一致。

朝鲜军队在施工过程中多次越过军事分界线，引发韩国军方发出警告广播和鸣枪示警。

2024年，朝鲜领导人金正恩将朝韩关系定义为“两个敌对国家”之间的关系后，朝鲜开始沿着军事分界线清理土地、埋设地雷、修建围栏、障碍物和战术道路。

韩国军方预计该项目将于 2028 年左右完工。截至 8 月，土地清理工作已完成约 90%，而围栏和雷区的建设预计已完成 30% 至 60%，具体完成情况取决于地区。

韩国国防分析研究所研究员柳智勋表示，即使非军事区的正式边界保持不变，防御工事建设活动也可能改变非军事区的军事性质。

“如果朝鲜在军事分界线附近设置围栏、雷区和战术道路等军事设施，即使非军事区的实际宽度保持不变，实际的军事缓冲区也会有效缩小，”柳说。

韩国国防安全论坛秘书长申钟宇指出，从军事分界线两侧各延伸2公里的非军事区一直起到防止冲突的缓冲作用，但朝鲜在非军事区内修建战术道路、围栏、障碍物和雷区可能会削弱这一作用。

“朝鲜所谓的边境防御工程仍在进行中，”一位联合参谋本部官员周五表示。

韩国国防部长康信哲将近期非军事区发生的地雷爆炸与朝鲜的防御工事建设联系起来。康信哲周二在国会发表讲话时表示，在爆炸地点附近发现的一枚朝鲜地雷似乎是人为埋设的，而非被冲入该地区的，并补充说，这枚地雷据信是“与边境防御工事建设有关”的。

韩国统一部长官郑东映周五抵达首尔政府大楼，回答记者提问。此前，他因朝鲜在非军事区发生地雷爆炸事件而缩短了欧洲之行。（韩联社）

然而，早在朝鲜开始最新一轮的防御工事部署之前，非军事区就已经布满了地雷。根据韩国联合参谋本部2020年提交给国会的数据，非军事区内估计埋设了38万枚地雷，而据估计，韩国境内仍遗留约82.8万枚地雷，其中包括靠近平民控制线和后方地区的地雷。

这些数字是截至 2020 年的估计值，并不代表目前剩余矿井的确切数量。

停战协定签署后，韩国军队也曾布雷，以防止朝鲜渗透并保护重要军事设施。但韩国联合参谋本部一位官员告诉《韩国时报》，针对朝鲜最近的军事行动，韩国并未在非军事区进行新的布雷或类似的防御工事建设，这与几十年前布设的雷区截然不同。

其中一个复杂之处在于，MDL 在其 248 公里的边界的大部分区域内不再有清晰的标记。

停战协定签署后，最初共设立了1292个界标来界定军事分界线。韩国国防部周五证实，目前仅存约250个界标。韩国和联合国军都根据停战协定地图、现存界标和地形地貌制定了自己的参考线，但双方在某些区域的评估结果并不一致。

与此同时，朝鲜将该边界称为其“边界”。朝鲜领导人金正恩的妹妹、实力强大的金与正否认朝鲜军队越过该边界。

“我们的士兵从未越过边界，”她周二表示。平壤方面尚未公开明确界定其认为的边界究竟在哪里。

据美国国防情报局评估，朝鲜军队在8月份越过军事分界线约20次，在9月份越过军事分界线约30次。

一名韩国联合参谋本部官员表示，朝鲜军队有时会在收到韩国方面的警告后，携带地图和望远镜返回现场，确认位置后再恢复工作。在某些情况下，他们还会转移工作地点。

9月21日，西部非军事区发生地雷爆炸，造成三名韩国士兵受伤，这些风险由此显现。随后的调查发现，在军事分界线以南还有一枚朝鲜埋设的杀伤人员地雷，联合国军司令部认定此举违反了停战协定。

韩国军方也在地形限制能见度的地区加强监视。“正在安装或计划安装更多监视设备，”一位联合参谋本部官员表示，但出于行动安全考虑，他拒绝透露具体位置。

统一部长官郑东荣周五提议与朝鲜进行会谈，以澄清军事决策界限。

钟先生说：“我们需要会面沟通。至少，我们应该开始对话，重新确认并明确多区诉讼案（MDL）的管辖范围。”

国防部一名官员表示，首尔方面“一直承认对军事判例的理解存在分歧，并承认需要进行磋商”，并指出正在与联合国继续进行讨论。