South Korea held an emergency security meeting on Sunday and pressed North Korea to keep reconciliatory deals as Pyongyang continued to up the ante by threatening to sever inter-Korean relations and even use military action.

Seoul's top security officials, led by Chung Eui-yong, director of national security at the presidential office, reviewed the current security situation on the Korean Peninsula as well as Seoul's response to the recent harsh rhetoric by Pyongyang, according to Cheong Wa Dae spokesman Kang Min-seok. 

The emergency security meeting came as Pyongyang built up tensions in inter-Korean ties with a threat to cut off all communication lines with South Korea last week.

Protesting against anti-North Korea leaflets sent by activists and North Korean defectors in the South, Pyongyang threatened to disconnect all telephone lines between the two Koreas last Tuesday.

Since then, the North has ratcheted up tensions with South Korea with a series of more harshly worded rhetoric, spearheaded by Kim Yo-jong, the powerful younger sister of North Korean leader Kim Jong-un.

Such threats culminated on Saturday as Yo-jong, first vice department director of the Central Committee of the Workers' Party of Korea (WPK), warned that Pyongyang would "break with" South Korea and signaled military action against Seoul.

"I feel it is high time to surely break with the South Korean authorities. We will soon take a next action," Kim said in a statement carried Saturday by the Korean Central News Agency.

The renewed tensions between South and North come as nuclear talks between Washington and Pyongyang have stalled for more than a year due to differences over the scope of North Korea's denuclearization and sanctions relief from the US.

Hours after Yo-jong's strongly worded statement, Seoul's unification ministry, which is in charge of inter-Korean relations, said the Seoul government is taking current situations seriously and that "the South and the North should adhere to all agreements (reached)."

In a related note, the South's defense ministry also said Sunday that it is maintaining a staunch readiness posture to respond to all situations involving North Korea, calling on the North to comply with the past inter-Korean military pact.

"The defense ministry is taking the current situation gravely and closely watching moves by the North Korean military," the ministry said in a statement, adding that it has maintained a staunch readiness posture "in preparation against all situations."

On Sunday, North Korea made public Yo-jong's Saturday statement to its own citizens.

The main newspaper, Rodong Sinmun, carried the full statement on the second page of its Sunday issue. Publishing additional articles linked with the statement in the Sunday edition, the newspaper also vowed "repetitive and thorough retaliation" against Seoul. (Yonhap)