A top US general on Thursday voiced concern over a possible "chain reaction" on the Korean peninsula if a planned South Korean artillery exercise leads to an aggressive response from the North.

South Korea had earlier announced plans for the live-fire exercise on Yeonpyeong island, its first on the frontline island since a similar drill unleashed a deadly North Korean bombardment there last month.

General James Cartwright, vice chairman of the US Joint Chiefs of Staff, said the live-fire exercise was being held on a "well-established and well-used" range in a transparent way, but could draw a North Korean reaction.

"What we worry about obviously is ... if North Korea were to react to that in a negative way and fire back at those firing positions on the islands, that would start potentially a chain reaction," Cartwright told reporters.

"What you don't want to have happen out of that is for ... us to lose control of the escalation. That's the concern," added Cartwright, who is the US military's second-highest ranking officer.

The South's military said its guns would be aimed away from the North, as usual, but that it would respond strongly if provoked.

It also said members of the US-led United Nations Command would observe the one-day exercise, to be staged some time between December 18 and 21.

Cartwright said about 15 US military trainers and six observers would be on hand for the drill.

State Department spokesman Philip Crowley said South Korea had a legitimate right to maintain its defenses.

"These are routine exercises. There is nothing provocative or unusual or threatening about these exercises," Crowley told a news conference.

"North Korea should not see these South Korean actions as a provocation," he said, adding that it would be "unwise" for North Korea to react.

earlier related report
S.Korea to hold live-fire drill on island shelled by N.Korea
Seoul (AFP) Dec 16, 2010 - South Korea on Thursday announced plans for a live-fire artillery exercise on Yeonpyeong island, its first on the frontline island since a similar drill unleashed a deadly North Korean bombardment there.

The South's military said guns would be aimed away from the North as usual during the drill this month, but added it would respond strongly if provoked.

"We will react firmly and strongly to any fresh North Korean provocations," Lee Boong-Woo, spokesman for the South's Joint Chiefs of Staff, told a briefing.

The military said members of the US-led United Nations Command would observe the one-day exercise, to be staged some time between December 18 and 21 depending on the weather "and other relevant conditions".

The Command, which supervises the armistice that ended the 1950-53 war, said about 20 US soldiers would attend the drill to provide medical and communications services and help with intelligence analysis.

The military has strengthened defences on the island by deploying surface-to-air missiles, more self-propelled howitzers and 130-millimeter multiple launch rocket systems, Lee said.

Some 120 residents still on the island will be advised to leave before the drill starts, he said, adding that those who want to stay will be taken to shelters. Two civilians were killed in the November bombardment by the North.

The nuclear-armed North insists the South's forces prompted its November 23 attack by firing shells into North Korean waters during a drill on the island near the disputed Yellow Sea border.

But the South says the North's attack was a deliberate provocation planned long in advance.

Seoul also announced on Thursday a major reshuffle to strengthen the military after fierce criticism of its perceived feeble response to the attack.

The shelling, the first of a civilian area in the South since the war, killed four people including two marines, damaged dozens of homes and triggered a regional crisis.

Marines on the island fired back at the North's artillery batteries but did not call in air strikes.

Defence Minister Kim Kwan-Jin, appointed after his predecessor resigned in the wake of the shelling, has vowed to use air power if there is any recurrence.

The North's state KCNA news agency, the mouthpiece of the Pyongyang government, reacted with an angry broadside accusing the minister of acting "reckless, like a puppy knowing no fear of a tiger".

It dismissed Kim's comments as "a spasm of a war maniac keen to ignite a war by increasing the tension on the Korean Peninsula".

The South's defence ministry on Thursday announced promotions for 111 officers -- 75 from the army, 14 from the navy and 22 from the air force.

"With this reshuffle, the military will strive to build strong armed forces that can fight and win and ensure firm combat-readiness," it said in a statement.

A new army commander, General Kim Sang-Ki, took office Thursday after his predecessor General Hwang Eui-Don quit over a controversial property investment.

North Korean leader Kim Jong-Il has inspected a military unit, KCNA said Thursday in the first report of such a visit since the November 23 shelling.

Kim was "greatly satisfied" to hear that its members are "keeping themselves highly vigilant against the aggression moves of the US imperialists and their stooges", it said.

The newspaper of North Korea's ruling communist party, Rodong Sinmun, meanwhile blamed current tensions on what it called the "policy of confrontation" by the conservative government in Seoul.

President Lee Myung-Bak dropped a "sunshine" engagement and aid policy and linked major assistance to nuclear disarmament, a stance which enraged the North.

"The South Korean authorities should roll back their treacherous 'policy towards the north' at once as they bring the dark clouds of nuclear war to hang over the peninsula," Rodong Sinmun said.