North Korea did not answer daily phone calls from South Korea via liaison and military hotlines on Tuesday after vowing to cut off all inter-Korean communication lines in anger over anti-Pyongyang leaflets sent from the South.

The decision to sever all phone lines at noon Tuesday was the latest in a series of angry protests the communist nation has made since last week while blasting Seoul for failing to stop North Korean defectors from sending propaganda leaflets criticizing Pyongyang's leadership.

Hours after announcing the decision, the North refused to answer a series of phone calls the South made Tuesday morning via liaison and military communication lines, officials at the unification and defense ministries said.

The South tried unsuccessfully to call the North again at noon.

"The inter-Korean joint liaison office attempted to call North Korea at noon, but the North did not answer," the unification ministry said.

It was unclear if the North has already cut off the phone lines. In the latest attempt, the phone was ringing, but the North didn't answer, ministry officials said.

South Korea urged the North to maintain the communication lines.

"Communication lines between the South and the North are a basic means of communication and should be maintained in accordance with inter-Korean agreements," a unification ministry official said. "While abiding by inter-Korean agreements, the government will make efforts for peace and prosperity on the Korean Peninsula."

Defense ministry spokesperson Choi Hyun-soo said it was the first time that the North has not answered military phone calls from the South since the hotlines were restored in 2018.

The North has denounced leaflet-sending as a hostile act breaching peace agreements the two sides signed during a series of summits in 2018, including a military tension reduction agreement that calls for a halt to all hostile acts along the border.

While announcing Tuesday's decision, the North said it will deal with the South as an "enemy."

"The disgusting riff-raff have committed hostile acts against the DPRK by taking advantage of the south Korean authorities' irresponsible stance and with their connivance. They dared to hurt the dignity of our supreme leadership," the Korean Central News Agency said.

"As far as the issue of the dignity of our supreme leadership is concerned, there can neither be a pardon nor an opportunity. They should be forced to pay dearly for this," it said.

The KCNA also said that the North "reached a conclusion that there is no need to sit face to face with the South Korean authorities and there is no issue to discuss with them, as they have only aroused our dismay."

"Accordingly, the relevant field of our side will completely cut off and shut down" all communications lines with the South at noon on Tuesday, including the hotline between the North's ruling Workers' Party and the South's presidential office Cheong Wa Dae, as well as a liaison line and military communication lines, the KCNA said.

The decisions were made at a meeting attended by Kim Yo-jong, sister of North Korean leader Kim Jong-un, and Kim Yong-chol, vice chairman of the Central Committee of the Workers' Party Korea (WPK), the KCNA said.

During the meeting, they "stressed that the work towards the South should thoroughly turn into the one against enemy" and discussed "phased plans" for such transition "in order to make the betrayers and riff-raff pay for their crimes."

The KCNA noted that cutting off all communication lines will be "the first step of the determination to completely shut down all contact means with South Korea and get rid of unnecessary things."

North Korean defectors and anti-Pyongyang activists in South Korea have occasionally sent balloons carrying leaflets sharply criticizing the communist regime and its leader, despite repeated calls for a halt to the campaign.

The balloons are often launched with US$1 bills and USB memory sticks to get more North Koreans to pick up the leaflets.

The North has been vehemently protesting propaganda leaflets since last week.

On Friday, the North's United Front Department (UFD) handling inter-Korean affairs issued a statement, saying it will abolish the liaison office in the North's border town of Kaesong in the first in a series of measures that the sister of leader Kim Jong-un threatened to take unless Seoul stops the sending of such leaflets.

The leader's sister also warned of dismantling a now-shuttered industrial park in Kaesong and scrapping a military tension reduction agreement signed in 2018, calling for a halt to all hostilities along the border.

North Korea vowed to put those threats into action, even though South Korea promised to take legislative measures to ban such activity. The North derided Seoul's envisioned move as "a little more advanced excuses."

The communication lines that the North vowed to completely cut off were established amid a peaceful atmosphere after South Korean President Moon Jae-in and North Korean leader Kim held three summits in 2018.

Inter-Korean relations have remained chilly amid stalemated denuclearization talks between Pyongyang and Washington since their no-deal summit in February last year. North Korea has balked at all of South Korea's offers for talks and cooperation. (Yonhap)