Friday, the South's Defense Minister Kim Kwan-jin said jets would bomb the North if it stages another attack, like the shelling last month on a front line island.
Kim took office Saturday, replacing a predecessor who resigned amid criticism that South Korea's response to the Nov. 23 attack was too slow and weak.
Four South Koreans were killed in the attack - two South Korean marines and two civilians.
Despite the recent attack, the Defense Ministry believes it's unlikely North Korea would launch a full-scale war as it could not wage a conflict for long and because of South Korea's solid military alliance with the U.S., Yonhap news agency reported Sunday citing the military.
The Associated Press contributed to this report.