SEOUL — North Korea said it would shut telephone hotlines with South Korea on Tuesday and ultimately sever all communications with its neighbor, hardening its policy as it attempts to gain concessions from Seoul.

The escalation came five days after Kim Yo Jong, the younger sister of North Korean leader Kim Jong Un, took charge of relations with South Korea and threatened to shut a joint liaison office and factory park in the border town of Kaesong.

Kim Yo Jong, who has been taking an increasingly high-profile role in Pyongyang, had demanded that Seoul prevent activists from sending leaflets across the border intended to promote democracy and undermine the nuclear-armed regime. In an attempt to salvage ties with the North, the South Korean government pledged to seek a legislative ban on the leaflets, angering human rights activists and others who questioned Seoul’s commitment to freedom of expression.

Pyongyang has hardened its rhetoric since nuclear talks with the United States broke down last year, and it has repeatedly signaled its fury at South Korea for implementing United Nations sanctions and failing to restart North-South economic cooperation projects.

North Korea said June 9 that it will sever hotlines with South Korea as the first step toward shutting down all contact with Seoul, state news agency KCNA said. (Reuters)

But the latest escalation may represent an attempt by Kim Yo Jong to assert her authority in a new, prominent position within the regime and an effort to exploit South Korea’s desire for better relations with the North.

The North’s official Korean Central News Agency said a communication channel at the liaison office, a direct hotline between the countries’ leaders and military hotlines would be closed as of noon Tuesday.

“This measure is the first step of the determination to completely shut down all contact means with South Korea,” the report said. “We have 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.”

The decision was announced by Kim Yo Jong and Kim Yong Chol, a former top nuclear envoy with a reputation as a hard-liner who appeared sidelined since talks broke down with Washington.

Pyongyang officials have decided to treat South Korea as an “enemy,” the report said, adding that they discussed phased plans to “make the betrayers and riffraff pay for their crimes.”

Officials from the two Koreas have been holding twice-daily phone conversations, at 9 a.m. and 5 p.m., since the liaison office was established in 2018. The North Korean delegation at the liaison office did not answer phone calls from South Korea on Tuesday morning, nor on Monday morning, for the first time since 2018, Seoul’s Unification Ministry said, although a call Monday afternoon was answered.

South Korea’s Defense Ministry said calls to the North via military hotlines also went unanswered Tuesday.

The cross-border phone lines were established in 2018 as an outcome of peace talks between Kim Jong Un and South Korean President Moon Jae-in.

“The inter-Korean hotlines are fundamental means of communication which should be maintained as per agreement between the Koreas,” South Korea’s Unification Ministry said. “Our government will keep the agreements between the two Koreas and make efforts toward peace and prosperity on the Korean Peninsula.”

Experts said Pyongyang appeared to be piling on pressure ahead of the 20th anniversary of an agreement on June 15, 2000, that was intended to pave the way for improved relations.

Jean Lee, a Korea expert at the Wilson Center, said the North knows that the lack of progress in cross-border relations is a “sore point” for the center-left Moon, who has made rapprochement with Pyongyang a focus of his presidency.

“North Korea is gaslighting South Korea ahead of the 20th anniversary of that June 15 milestone because they know Seoul wants a relationship so badly,” she tweeted. “And to distract their own people from the reality of their economic hardship.”

Denyer reported from Tokyo.