North Korea announced on Wednesday that it will permanently seal its border with South Korea and construct defensive structures along the frontier. These actions are being taken to counter what the North calls the “confrontational hysteria” of South Korean and US forces. While the announcement of a constitutional revision to formally declare South Korea its primary enemy and establish new national borders was anticipated, it was not included in the statement.

Although these moves are likely a pressure tactic, their impact on relations with South Korea remains unclear, given that cross-border travel and exchanges have been suspended for several years.

According to the North’s official Korean Central News Agency (KCNA), the North Korean military stated that it will “completely cut off roads and railways” connecting to South Korea and “fortify the relevant areas on our side with strong defense structures.”

The North’s military characterized its actions as a “self-defensive measure for inhibiting war and defending the security” of North Korea. It attributed these steps to the “ever more reckless confrontational hysteria” of what it considers hostile forces. These forces, according to North Korea, include various war exercises in South Korea, the deployment of US strategic assets, and what it perceives as aggressive rhetoric from its adversaries.

South Korea’s military responded later on Wednesday, stating that it will not tolerate any attempt by North Korea to alter the status quo. It declared that South Korea will “overwhelmingly punish” North Korea for any provocations. A statement issued by the South Korean military asserted that North Korea’s nuclear and missile programs pose a threat to peace on the Korean Peninsula.

South Korean officials had previously reported that North Korea had been reinforcing its border since April by installing anti-tank barriers and strengthening roads. This effort was likely intended to enhance front-line security and prevent soldiers and citizens from defecting to South Korea. In a report to parliament on Tuesday, South Korea’s Unification Ministry revealed that North Korea has been removing ties on the northern side of cross-border railways, dismantling nearby lamps, and laying mines along the border.

Earlier on Wednesday, KCNA reported that the Supreme People’s Assembly convened for two days this week to amend the legal ages for North Koreans to participate in employment and elections. However, the report made no mention of whether the meeting addressed the order issued in January to revise the constitution. This revision aimed to remove the objective of a peaceful Korean unification, formally designate South Korea as the country’s “invariable principal enemy,” and define North Korea’s sovereign territorial sphere.

A central focus of international attention was whether North Korea would assert new legal claims over the waters currently off their western coast. The poorly marked western sea boundary has been the site of three bloody naval skirmishes and two deadly attacks attributed to North Korea in the past 25 years.

Some experts believe that North Korea may have postponed the constitutional revision, while others speculate that the amendment may have taken place without public announcement due to its sensitivity.

Kim’s order took many North Korea watchers by surprise, as it was seen as a departure from the long-held aspirations of his predecessors to achieve a unified Korea on North Korea’s terms. Experts suggest that Kim’s objective is likely to diminish South Korea’s influence in the regional nuclear standoff and seek direct negotiations with the US. They also believe that Kim aims to curtail South Korean cultural influence and strengthen his domestic control.

Tensions on the Korean Peninsula are at their highest point in years, fueled by North Korea’s continued series of provocative weapons tests and the expansion of military drills by South Korea and the US. KCNA reported that North Korea tested a long-range artillery system on Tuesday, which observers consider a direct threat to Seoul, the South Korean capital, located only an hour’s drive from the border.