Hagel agrees strategy with Seoul to deal with threat from North Korea

South Korea and the United States have mapped out a new strategy to counter the growing threat of a North Korean nuclear or chemical weapons attack, their defence ministers said yesterday.

They also agreed to review the sensitive issue of when Seoul should assume operational wartime command over their combined forces in South Korea.

Visiting US Defence Secretary Chuck Hagel said the new pact signed with his South Korean counterpart, Kim Kwan-jin, established a "strategic framework" for dealing with "key North Korean nuclear threat scenarios" in the wake of its third atomic test in February.

Kim said the plan would "greatly enhance" the alliance's deterrence capacity.

Observers said it was largely a confidence-building measure to underline Washington's support for Seoul against any provocation from Pyongyang.

South Korea is protected by the US nuclear umbrella and there are nearly 30,000 US troops stationed in the country.

But Seoul insists that the alliance must respond to what Kim described as the "vastly different" security situation on the Korean peninsula following the North's nuclear test. It has requested an extension of US wartime command over South Korean troops, which is currently scheduled to end in 2015.

In the event of war with North Korea, the alliance at present calls for the US commander to lead the US troops deployed to the country, as well as South Korea's 640,000-strong force.

Seoul argues that the transition to South Korean command should be postponed until the nuclear threat from Pyongyang has been neutralised.

Washington has indicated it wants to keep to the original schedule, but Hagel said he had listened "very seriously" to Seoul's concerns and promised further consultations.

"We are very optimistic we will have an agreement," he added. At a joint press briefing with Kim, Hagel also stressed that the new deterrent strategy covered all the North's weapons of mass destruction, including chemical weapons.

South Korean defence officials say North Korea has up to 5,000 tonnes of chemical arms.

"There should be no doubt North Korean use of chemical weapons would be completely unacceptable," Hagel said.

The North's nuclear test in February - its third and most powerful to date - triggered months of heightened tensions on the Korean peninsula.

"North Korea has increased its threat clearly against South Korea, and against the United States. It has increased its capability," Hagel said.

But he also said South Korea's military has grown "stronger, more professional and more capable" in the past decade.