President Park Geun-hye on Monday directed her government to maintain "full readiness" against possible North Korean provocations as security concerns grow following the execution of Jang Song-thaek, the uncle of the North's ruler Kim Jong-un.
During a meeting of top foreign affairs and security officials at Cheong Wa Dae, Park also called on her staff to strengthen security cooperation with the United States, beef up border patrol and tighten discipline in officialdom.
The president also ordered the establishment of a standing secretariat of the National Security Council.
"The current situation on the peninsula and our security conditions are very serious, and the government should ensure full readiness to relieve people of security concerns, so that they can do their business as usual," she was quoted as saying by her chief press secretary Lee Jeong-hyun.
"While keeping close tabs on North Korea, the government should come up with measures to prepare itself against all scenarios, and strengthen the readiness posture of the military and police."
The meeting was attended by National Security Office chief Kim Jang-soo, senior presidential secretary Ju Chul-ki, National Intelligence Service director Nam Jae-joon, Defence Minister Kim Kwan-jin, Foreign Minister Yun Byung-se and Unification Minister Ryoo Kihl-jae.
Earlier in the day, Park warned against "reckless" North Korean provocations.
"If you look at the recent series of developments in North Korea, it is unclear how the situation will unfold. Sudden unexpected incidents such as reckless provocations cannot be ruled out as well," Park said during a weekly meeting with her senior secretaries.
"Given the gravity and unpredictable nature of the current North Korean situation, we, the citizens, the government and the military, should make concerted efforts to continuously prepare against (provocations)."
After Jang was abruptly executed last week for plotting to overthrow his nephew's regime, analysts said that the case underscored the growing insecurity of the fledgling ruler and signs of a power struggle among elites.