Seoul's presidential Blue House strongly denounced North Korea's killing of the South Korean civilian calling it an inhumane atrocity.
Unacceptable said President Moon Jae-in and called on North Korea to "take full responsibility and clarify the truth."
Arirang News' senior Blue House correspondent Kim Min-ji is live at the top office.
Min-ji, the presidential office has been on high alert since news broke out this morning.
Yes. Multiple meetings and briefings here at the top office today.
In the latest President Moon has called the incident "shocking" saying that it cannot be tolerated for any reason.
His remarks come after he was briefed this afternoon on the results of the National Security Council meeting which convened to discuss response measures to the killing of the South Korean national.
Here's the presidential spokesperson.
"President Moon said that North Korea must offer an explanation and take responsible measures. He also ordered the military to further strengthen its security posture and ensure it is fully prepared to protect the lives and safety of the people."
The NSC earlier issued a statement condemning North Korea's killing of the South Korean official calling it inhumane and an act that goes against international regulations.
It said that Pyeongyang must apologize and reveal the entire truth warning that Seoul will respond resolutely to any act that threatens people's lives and security.
A Blue House official told reporters that an emergency meeting was held at the top office on the wee hours of Wednesday to analyze intelligence that the man had been shot dead and his body burned.
Hours later, President Moon was briefed on the outcome and ordered officials to confirm the details with the North Korean side and let the people know exactly what happened.
No response from Pyeongyang as of yet.
When asked whether South Korea sees any involvement by North Korean leader Kim Jong-un, the Blue House said that the intelligence needs to be analyzed further.
Minji, the incident must be a blow to President Moon's efforts to improve relations with the North.
Less than 48 hours ago, President Moon's speech to the United Nations was being played to the General Assembly where he called for a formal end to the Korean War.
Now, we're learning that while Moon was giving the speech at the UN, his office was already holding meetings on the South Korea's disappearance at sea.
Is this not a violation of the 2018 military agreement signed by the two Koreas in which both sides vowed not to engage in hostilities?
Well, the top office says that the incident is not a violation of the military agreement because the deal does not regulate the use of small firearms.
However, it did say that it goes against the spirit of the deal which aims to ease tensions and build trust.
As for President Moon's UN address, the top office said it was pre-recorded on the 15th and sent to the UN on the 18th so it had no relevance to the recent incident.
In the speech, Moon called for a declaration to end the 1950-53 Korean War.
Mind you, the latest development is expected to deal a blow to inter-Korean relations, and put the brakes on the Moon administration's efforts to revive the peace process.
For now, the top office is expected to keep close tabs on the situation, while waiting for a response from North Korea.
Back to you Conn-young.