Kim You-geun, deputy director of Cheong Wa Dae's national security office, speaks during a press briefing at Cheong Wa Dae, Tuesday. Yonhap

Hours after North Korea demolished the inter-Korean liaison office in its border town of Kaesong in a surprise provocation Tuesday, South Korea warned of a strong response if the North further worsens the situation.

Cheong Wa Dae made the unusually strong warning after holding an emergency meeting of the National Security Council (NSC) standing committee to discuss the matter.

"The government expresses strong regret over North Korea's unilateral explosion of the inter-Korean liaison office building," Kim You-geun, deputy director of Cheong Wa Dae's national security office, told reporters after the meeting. "We sternly warn that we will strongly respond to it if North Korea takes any action that further worsens the situation."

Kim also said the demolition constitutes an action that betrays "the expectations of all people who wish for the development of inter-Korean relations and the settlement of peace on the Korean Peninsula."