North Korean leader Kim Jong Un hosts a military meeting of the ruling Workers' Party to discuss new policies aimed at boosting the country's nuclear deterrence. (KCNA/Kyodo)

BEIJING - North Korea will cut off all lines of communication with South Korean authorities, state-run media reported Tuesday, in protest at defectors recently launching balloons over the border containing leaflets critical of Pyongyang.

"This measure is the first step of the determination to completely shut down all contact means with South Korea and get rid of unnecessary thing," the official Korean Central News Agency said.

The lines of communication to be severed include one at an inter-Korean liaison office as well as lines between the two countries' militaries and between South Korea's presidential office and North Korea's ruling Workers' Party of Korea.

Routine calls to North Korea via the liaison office and military communication lines at 9 a.m. already went unanswered, according to the South Korean government.

South Korea under President Moon Jae In has tried to forge friendly ties with North Korea. But the North's hardening stance toward the South is likely to further test the fragile ties between the two neighbors.

Observers say North Korea is likely to continue its tough stand against South Korea in a bid to maintain its control of the country as it tries to minimize the impact of the coronavirus pandemic on its economy.

Pyongyang's decision was made Monday at a meeting attended by North Korean leader Kim Jong Un's sister, Kim Yo Jong, and Kim Yong Chol, a vice chairman of the ruling party, the KCNA report said.

Kim Yong Chol emphasized that the stance against South Korea "should thoroughly turn into the one against enemy," according to the news agency.

Kim Yo Jong, first vice department director of the party's Central Committee, warned in a statement last Thursday that Pyongyang may scrap a military pact with the South if Seoul fails to prevent defectors from sending leaflets critical of the North.

She threatened to completely dismantle an industrial park in the country's border city of Kaesong as well as shutting down the liaison office located there.

Kim Yo Jong, North Korean leader Kim Jong Un's sister, pictured in Pyongyang in September 2018. (Kyodo)

At their first summit in April 2018, Kim Jong Un and Moon signed a declaration in which the two Koreas agreed to establish a joint liaison office and cease all hostile acts, including sending leaflets, to eliminate the risk of war.

Kim Yo Jong has increasingly become the public face of North Korea in its dealings with South Korea. According to a statement from a party spokesman issued Friday via KCNA, she now supervises policies toward the South.

The latest North Korean move comes after the two Koreas saw little progress in cooperative projects promised by the two leaders in a series of talks in 2018. North Korea is still facing international economic sanctions aimed at thwarting its nuclear and ballistic missile ambitions.

Following Kim Yo Jong's threats, the South Korean government said last week it was planning to legislate a ban on sending anti-Pyongyang leaflets across the border.

Anti-South rallies have been held in North Korea for days. On Monday, young people and students held a procession on the streets of Pyongyang protesting against the scattering of leaflets by defectors over the border, according to state-run media.