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.
The South's 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 service and assist in intelligence analysis.
The military said guns during the upcoming drill would be aimed away from the North.
"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 North insists the South's forces provoked its November 23 attack by lobbing shells into North Korean waters during a drill on Yeonpyeong island, near the disputed Yellow Sea.
The South says the North's attack was a provocation planned long in advance.
Seoul also announced a major reshuffle to strengthen the military after fierce criticism of its perceived feeble response to the North's attack.
The North's shelling, the first of a civilian area in the South since the war, killed four people including civilians, damaged dozens of homes and triggered a regional crisis.
Leader Kim Jong-Il has inspected a military unit, Pyongyang's state news agency said Thursday in the first report of such a visit since November 23.
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 South has vowed to hit back harder for any future attack.
Marines on the island fired back at the North's artillery batteries last month but did not call in air strikes.
New Defence Minister Kim Kwan-Jin, appointed after his predecessor resigned, has vowed to use air power if the North attacks again.
The defence ministry 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.
Rodong Sinmun, newspaper of the ruling communist party, 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.