South Korean President Lee Myung-bak has told his nation it must unite in the face of military aggression from the North.
Mr Lee said in a national radio address that what was at stake was "the survival of this nation".
He added: "If [we] are afraid of war, we can never prevent war".
The Korean peninsula has been tense since the North shelled the Southern island of Yeonpyeong last month, killing four people.
On Sunday, it was announced that South Korean and Chinese defence ministers would meet in Beijing in February for talks on the situation. BBC News
