Acting President and Prime Minister Hwang Kyo-ahn ordered troops Tuesday to be on guard against North Korea's possible provocations in the wake of President Park Geun-hye's ouster.

Hwang made the remark during a visit to the wartime command post of the Joint Chiefs of Staff, where South Korea-US military drills are under way.

It marked his first on-site inspection since the Constitutional Court ruled to dismiss Park over a corruption scandal on Friday.

"The military must ensure a firm defense posture by doing things like tightening its guard to deter North Korea from carrying out reckless provocations based on a misjudgment of our domestic situation," he said.

North Korea fired five ballistic missiles this year alone and revealed its cruelty in the assassination of Kim Jong-nam, the estranged half brother of leader Kim Jong-un, he noted.

"The South Korea-US joint drills are defensive exercises aimed at deterring North Korean provocations and have played a vital role in defending peace on the Korean Peninsula and in Northeast Asia," Hwang said.

North Korea has long denounced the drills as a rehearsal for an invasion against it.

Hwang said the Joint Chiefs of Staff played a key role in the lead-up to this year's Key Resolve exercises by writing up the preparatory documents, which will serve to enhance its leadership role down the road.

He also urged all exercises to be built to instill a sense of confidence in troops that they will win in the event of an armed conflict. (Yonhap)