North Korea vowed Friday to abolish an inter-Korean liaison office in the first in a series of measures in anger over anti-Pyongyang leaflets sent from South Korea, even after Seoul promised to ban such leaflet campaigns.

The United Front Department, which handles inter-Korean affairs, said in a statement that leader Kim Jong-un's sister, Kim Yo-jong, ordered officials to look into implementing a series of measures she threatened to take a day earlier unless Seoul stops North Korean defectors from sending such leaflets.

The hardline statement came despite South Korea's promise to take legislative measures to ban flying-in of propaganda leaflets, and appears to be aimed at increasing pressure on Seoul to make sure to follow through with its pledge.

"Our determination is to follow as far as the evil cycle of the confrontation leads while facing the situation squarely, because our path is always straight," an unnamed spokesperson of the UFD said in a statement carried by the Korean Central News Agency.

"As the first thing, we will definitely withdraw the idling North-South Joint Liaison Office housed in the Kaesong Industrial Zone to be followed by effectuation of various measures which we had already implied," the spokesperson added.

Closing the liaison office was one of the measures that the leader's sister threatened to take, along with scrapping an inter-Korean military tension reduction agreement and completely dismantling a now-shuttered joint industrial park.

In Friday's UFD statement, the North also confirmed she is the top official handling inter-Korean issues as it said the South should "read each word and phrase" of her statement because the warning was issued by the one "looking after affairs with South Korea."

Her official title is first vice department director of the Central Committee of the Workers' Party.

Shortly after her warning Thursday, South Korea called for an immediate halt to such leaflet-sending and pledged to legislate a ban on such activity. The office of President Moon Jae-in also said that leaflet-sending does "no good but harm" and should be dealt sternly with.

But the North called the envisioned legislation "a little more advanced excuses."

"Then does it mean that they signed the agreement in the military field on halting all the hostile acts in the areas along the Military Demarcation Line with no definite guarantees like such a bill," the spokesperson said.

"Then even though we start things that can be annoyance to the South in the area bordering it, it will be left with no words until the bill is adopted and put into effect," the spokesperson added.

North Korean defectors and anti-Pyongyang activists have occasionally sent a large number of leaflets via giant balloons sharply criticizing the communist regime and its leader. These are often flown with one-dollar bills and USB memory sticks to get more North Koreans to pick up the leaflets.

South Korea's government has advised against sending such leaflets, citing concerns about the safety of residents in the regions where the leaflet-carrying balloons are launched because the North could take retaliatory military action on the areas.

Defector groups and anti-North Korea civic organizations have often ignored such an appeal, citing their right to freedom of expression. Under the current law, it is also impossible to ban the leaflet campaign.

North Korea has strongly bristled at anti-Pyongyang leaflets sent across the border, seeing them as a serious hostile act aimed at undermining the authority of its leaders.

The latest warning came as cross-border relations have been chilled amid a stalemate in denuclearization talks between Pyongyang and Washington since the no-deal summit in February last year between the North's leader and US President Donald Trump., which handles inter-Korean affairs, said in a statement that leader Kim Jong-un's sister, Kim Yo-jong, ordered officials to look into implementing a series of measures she threatened to take a day earlier unless Seoul stops North Korean defectors from sending such leaflets.

The hardline statement came despite South Korea's promise to take legislative measures to ban flying-in of propaganda leaflets, and appears to be aimed at increasing pressure on Seoul to make sure to follow through with its pledge.

"Our determination is to follow as far as the evil cycle of the confrontation leads while facing the situation squarely, because our path is always straight," an unnamed spokesperson of the UFD said in a statement carried by the Korean Central News Agency.

"As the first thing, we will definitely withdraw the idling North-South Joint Liaison Office housed in the Kaesong Industrial Zone to be followed by effectuation of various measures which we had already implied," the spokesperson added.

Closing the liaison office was one of the measures that the leader's sister threatened to take, along with scrapping an inter-Korean military tension reduction agreement and completely dismantling a now-shuttered joint industrial park. (Yonhap)