South Korea expressed regret over North Korea’s blow up of liaison office.

SEOUL, South Korea —
South Korea hit back hard at North Korea with harsh criticism on Wednesday after Pyongyang blew up an inter-Korean liaison office building in Kaesong, North Korea, in a show of force expressing discontent with the South Korean government.

“This is a fundamental breach of trust that the leaders of South and North have built up until now, and we are clearly warning that we will no longer tolerate these irrational remarks and actions by the North,” Yoon Do Han, South Korean president’s senior secretary for Public Communication said in a briefing Wednesday.

The tone and selection of words were strongest since South Korean President Moon Jae-in took office. This rare jab at North Korea follows an embarrassing exposure by Pyongyang Wednesday morning, saying the North Korean leader’s sister Kim Yo Jong “flatly rejected the tactless and sinister proposal” from the South Korean president to send a special envoy to Pyongyang.

“We are extremely displeased to get such an absurd judgment and reckless proposal,” North Korea said in a statement carried on its state media, Korean Central News Agency.

In response, Moon’s senior secretary expressed “strong regret” to North Korea for “intentionally distorting the purpose of sending a special envoy to North Korea” by publicly revealing South Korea’s privately offered proposal to send a special envoy to overcome the current crisis. “This is an unprecedented senseless action,” Yoon added.

North Korea has accused the South of behaving like a “mongrel dog” bent on confrontation, vowed to dispatch military troops in and around Mount Kumgang Tourist Region, Kaesong Industrial Complex and DMZ’s guard posts, and resume military training in the West Sea. These areas were cleared of military presence in the past few years in accordance with an agreement reached between the two leaders of North and South Korea.

North Korea also stated that it would open all front-line areas that are advantageous to send leaflets to the South.

ABC News’ Heejin Kang contributed to this report.