Seoul - Lee Myung Bak on Tuesday became the first South Korean president in five years to preside over a national security meeting in the wake of a series of threats from North Korea.

The focus of the annual gathering - which brought together 200 military, intelligence, security and local government officials - is defending South Korea from "enemy infiltration and provocation of limited scale," the Defence Ministry said.

South Korea fears tensions with its Stalinist neighbour could escalate into a limited military altercation, possibly over the two countries' contested border in the Yellow Sea.

Pyongyang has threatened Seoul with annihilation several times over the past weeks and in late January scrapped bilateral reconciliation agreements and nullified an agreement over its sea border with the South. It accuses Lee's government, in office for a year, of pursuing a confrontational policy.

The security meeting came the same week that South Korea is to publish a security policy document that would for the first time describe North Korea as both an "immediate and grave threat," according to the Defence Ministry. The so-called white book is to be released Friday.

Meanwhile, on Monday, North Korea indicated it was preparing to launch a multiple-stage rocket. It said in its official media that the launch was aimed at "space development."

However, intelligence reports from South Korea and the United States said that activity around an east coast launch site in North Korea indicated it was planning a test of its Taepodong-2 intercontinental ballistic missile, and South Korean Defence Minister Lee Sang Hee told the National Assembly that the North had been preparing for a Taepodong-2 test since January.

According to the US military, the Taepodong-2, when technically perfected, could reach the US state of Alaska and carry a nuclear warhead. (dpa)