In the face of military aggression from North Korea, the South must unite, said its president Lee Myung-bak during a national radio address.
He said that “the survival of this nation” is at stake, before adding : “If [we] are afraid of war, we can never prevent war.”
Last month, tension rose between the two countries after the North shelled the Southern island of Yeonpyeong, killing four people.
On Monday, president Lee also said : “We can’t afford to have division of you against me in the face of national security, because what’s at stake is our very lives and the survival of this nation.”
According to him, last month’s attack on Yeonpyeong island was brought by divisions of opinion following the North’s alleged sinking of a Southern warship in March, which killed 46 sailors.
The South Korean president added : “It is when we show solidarity as one that the North dares not challenge us. Their will to challenge breaks.”
“We have clearly realised the fact that only strong counteractions to military provocations are able to deter war and safeguard peace.”
After the Yeonpyeong attack, Lee’s government was described as weak by some people in South Korea.
Following the incident, South Korea replaced its defence minister and the country has embarked on a series of military exercises while ratcheting up its rhetoric.
Even though it has not retaliated militarily, last week North Korea vowed a “sacred war”.
The country denies the South’s accusations, saying that it did not sink the warship and that its shelling of the island was retaliation for a South Korean firing drill that dropped shells into North Korean territory.
The North warned in a commentary on Monday in state daily Rodong Sinmun that joint US-South Korean exercises were “reckless military provocation”.
“There is limit to our patience,” the commentary said.
President Lee finished his speech by saying that his country still wanted a peaceful reunification with the North.
In February, South Korean and Chinese defence ministers will meet in Beijing in order to talk about the situation.