SEOUL, South Korea (AP) - South Korea and the United States will hold joint anti-submarine exercises in another show of force against North Korea, officials said Friday, as Pyongyang renewed threats against the drills.

The exercises will be the second in a series of joint maneuvers the allies planned to conduct in response to the deadly sinking of a South Korean warship in March that they blame on the North. The two sides staged large-scale joint naval drills in July followed by South Korea's own naval drills last month.

The drills, set to run from Sunday through Thursday off the Korean peninsula's west coast, will involve about 17,000 U.S. and South Korean troops, seven ships and two submarines as well as aircraft, according to South Korea's Joint Chiefs of Staff and the U.S. military in Seoul.

The exercises are "designed to send a clear message of deterrence to North Korea, while improving overall alliance anti-submarine warfare capabilities," the U.S. military in Seoul said in a statement.

The announcement of the planned drills comes as China reportedly holds live-ammunition exercises in the Yellow Sea.

An international team of investigators concluded in May that a North Korean torpedo sank the 1,200-ton South Korean warship Cheonan in late March near the Koreas' western maritime border, killing 46 South Korean sailors.

North Korea, which denies any involvement in the sinking, has threatened to retaliate against South Korea and the U.S. over the drills, which Pyongyang sees as a rehearsal for an invasion.

The U.S. keeps 28,500 troops in South Korea in what it says is a deterrent against any possible aggression from North Korea and says it has no intention of invading the North.

"Our military and people will deal a merciless blow if warmongers stage reckless provocation," North Korea's government-run website, Uriminzokkiri, said in a commentary Friday.

North Korea often makes such threats, though the joint maneuvers in July and South Korea's independent exercises took place without incident.

The two Koreas officially remain at war because the 1950-53 Korean War ended with an armistice, not a peace treaty.

South Korean and U.S. troops recalled that war Friday, dressing in period uniforms to re-enact a crucial battle, including the blowing up of a bridge. The battle took place in 1950 in a narrow area known as the Pusan Perimeter. U.S. and South Korean troops mounted a desperate defense against advancing North Korean soldiers that was crucial in turning the tide of the war.