"I call on the military to maintain a robust readiness posture to sternly retaliate against any types of North Korea's military threats," Hwang said during the ceremony at the National Cemetery in Daejeon, 164 kilometers south of Seoul.

"There is a possibility that North Korea, by misjudging our situation, will stage yet another reckless military provocation," he added.

Park was dismissed on March 10 after the Constitutional Court upheld her impeachment over a massive corruption scandal. Though the country is set to hold an election on May 9 to pick Park's successor, concerns over a leadership vacuum have persisted.

Pointing to a recent series of Pyongyang's saber-rattling, Hwang highlighted that Seoul, in tandem with the international community, has been striving to toughen economic sanctions and diplomatic pressure on the wayward regime to have it change tack toward denuclearization.

In recent months, the North has been ratcheting up military tensions here with a series of missile tests and a high-thrust rocket engine experiment, which observers said indicate it is on course to develop a nuclear-tipped intercontinental ballistic missile.

Before the ceremony, Hwang paid respects before the graves of South Korean troops that were killed in a series of North Korean provocations in the West Sea, including its torpedo attack on the Cheonan corvette in 2010.
Since last year, the Seoul government has observed the special day to remember those fallen soldiers. (Yonhap)