The Donghae Line survey team, consisting of South Korean government officials and railway experts, take a bus to North Korea to inspect the Donghae Line railway along the eastern coast, in this Dec. 8, 2018 file photo. Yonhap

North Korea has demolished street lamps on land routes connecting the two Koreas, in what observers say is a signal to South Korea that its leader Kim Jong-un is serious about abandoning the goal of peaceful unification with the South.

The military confirmed on Thursday that North Korea has recently torn down street lamps along the Gyeongui road, which was used mainly for connecting the North's Kaesong Industrial Complex to South Korea, and the Donghae road, which was used for traveling to Mount Geumgang and sending food aid to the North.

"We recently detected that North Korea has dismantled street lamps, and are closely monitoring their military activities. We are analyzing the motive behind dismantling. It currently has no military impact," Col. Lee Sung-jun, spokesperson of the Joint Chiefs of Staff, said in a press briefing Thursday.

This comes after North Korean troops were spotted installing mines on two roads in January as inter-Korean relations have become increasingly strained in recent months. Last December, Kim said that inter-Korean relations had become "a relationship between two hostile countries and two belligerents at war," the North's state-run Korean Central News Agency said.

The Ministry of Unification said demolishing street lamps on two roads is a clear act of violating the inter-Korean agreement, urging North Korea to repay millions of dollars in loans provided to build the roads.

"Pyongyang is obligated to repay the loans to Seoul. Construction of the Gyeongui and the Donghae railway development and road linkage projects were funded by loans from the South Korean government, but the North has not paid a penny yet," a ministry official said.

The South Korean government provided loans worth $132.9 million to North Korea from 2002 to 2008. However, the final loan amount has not been confirmed, as the constructions were halted before they were completed.

The official said North Korea's intention of dismantling street lamps may have to do with a lack of materials.

"Another possibility might be to collect and reuse scrap metal from the demolition of street lamps," the official said.

The two inter-Korean roads were built in the mid-2000s during a reconciliatory mood on the Korean Peninsula but have ceased to function as ties have soured in recent years.

The Gyeongui road was last used when South Korean officials withdrew from a joint liaison office in Kaesong in 2020 due to the COVID-19 pandemic. The Donghae road has remained unused since the 2019 Hanoi summit between Kim and then-U.S. President Donald Trump.