South Korean President Lee Myung-bak named on Friday a retired general to head a newly created office for national crisis management as two attacks from North Korea this year raised tension on the peninsula.
The office was set up this month in response to questions over whether the South was prepared to defend itself against surprise attacks by the North after it shelled a southern island last month killing four people.
Lee also named a trusted economic aide as minister for knowledge economy in charge of industrial and energy policy and a political ally the minister for culture. Lee is about to start the final two years of his single five-year term.
The head of the crisis management office is retired major general An Kwang-chan. He previously served as the defense ministry's policy planning chief and at the Combined Forces Command made up of US and South Korean militaries that organise defensive operations against the North.
South Korea said on Thursday the immediate threat from the North had grown with Pyongyang deploying 20,000 more special warfare troops near the border and adding tanks to its mechanised divisions.
South Korea reinstated its "enemy" designation for the North this year after having dropped it in 2000. South Korea and its allies blamed the North for torpedoing a South Korean navy ship in March killing 46 sailors.
The November bombardment of a South Korean island by North Korean artillery units sharply escalated tension and the South vowed to deal "a merciless counterattack" in the event of more North Korean aggression.
Analysts said the chance of a wider conflict had grown as tension mounted, but many do not expect the rival Koreas to engage in an all-out war.
The new minister for knowledge economy is Choi Joong-kyung, while Choung Byoung-gug in minister for culture.