North Korea has officially declared South Korea as “a hostile state” in its revised constitution, a move that comes just two days after Pyongyang blew up the key road and railway links with its neighbor.

The official Korean Central News Agency (KCNA) reported on Thursday that the military destroyed the 60-meter-long stretches of road and rail along the east and west sections of the inter-Korean border “as part of the phased complete separation” of its territory from South Korea on Tuesday.

North Korea said it was “an inevitable and legitimate measure taken in keeping with the requirement of the DPRK constitution which clearly defines the ROK as a hostile state,” using the North’s official name, the Democratic People’s Republic of Korea, and that of South Korea, the Republic of Korea, respectively.

A spokesman from the Ministry of Defense said that Pyongyang plans to implement additional steps to “permanently fortify” its border, according to the KCNA, while not addressing any other constitutional amendments mandated by leader Kim Jong-un.

In response, South Korea strongly condemned North Korea’s constitutional reference as a hostile state, labeling the move as “an anti-unification, anti-national act,” South Korea’s Unification Ministry, which handles ties with the North, said.

The move to label South Korea a “hostile state” comes after North Korea’s Supreme People’s Assembly convened for two days last week to rewrite the country’s constitution, but state media remained silent on the specifics of the discussions, fueling speculation that the constitutional changes may have been delayed.

In January, Kim declared that reunification with South Korea was off the table, proposing a constitutional amendment to define the South as a separate “hostile” country.

“We don’t want war, but we have no intention of avoiding it,” Kim said, accusing Seoul of conspiring with the United States to undermine his government.

Tensions on the Korean Peninsula have escalated, as North Korea has accused South of conducting drone flights over Pyongyang three times this month, threatening severe military retaliation for any future incursions.

Relations between the two Koreas remain at one of their lowest points in years, especially since Kim declared in January that the South is his government’s number one enemy. 

This comes as senior political and military officials in Pyongyang also say they do not expect any future changes in their relations with the West.

Kim has repeatedly said that Pyongyang is strengthening its armed forces to confront the US and its regional allies in a war that could “break out at any time” on the Korean Peninsula.