South Korea  said on Sunday bad weather was delaying the start of a  live-fire exercise that prompted North Korean threats of war,  adding that it had no plans to scrap the drills despite  international calls for restraint.

The UN Security Council is expected to convene an  emergency session on Sunday on the escalating tension between  North and South Korea in the hope of issuing some kind of  statement to help ease the tension in the region.

North Korea has called the artillery fire drill by the  South, on Yeonpyeong island which was attacked last month, a  suicidal war move that would trigger a full-out conflict on  the Korean peninsula and said it would strike back in  self-defense.

Analysts were sceptical the North would carry out the  threat it issued on Friday, which rattled financial markets,  but it added to the already tense situation in the peninsula  which has been described as "extremely precarious" and a  "tinderbox" by US and Chinese officials.

The North will likely respond by holding a live-fire drill  on its side of the tensely guarded sea border, if the South  went ahead with its exercise, analysts said.

Weather conditions worsened on the normally sleepy,  idyllic island of fishermen, forcing the military to push back  a planned one-day live-fire drill past the weekend. It had  been scheduled for some time between December 18 and 21.

"There is no plan to cancel the exercise. The factor we're  looking at is the weather condition," a Defence Ministry  official said on the condition of anonymity.

South Korean marines plan to test artillery firing from  the island targeting its territorial waters to its southwest,  the same type of exercise that North Korea last month called  an attack and returned fire, killing four people.

US troubleshooter Bill Richardson, the governor of New  Mexico who is on a private mission to Pyongyang, said he had  made some progress in his discussions with officials there.

He told CNN he did not get a firm answer on whether North  Korea would physically strike the South again, but added:  "It's still very tense out there" .

"They said there would be a response, but at the same time  they hope a UN Security Council resolution would tamp down  the situation. It was very clear they were very upset by the  potential exercise," Richardson told CNN from Pyongyang. - Reuters