SEOUL (AFP) - South Korea and the United States on Friday conducted a joint naval drill ahead of the launch next week of large-scale military exercises that have incensed North Korea.

The drill involved 10 South Korean warships, backed by surveillance planes and helicopters, as well as a US Aegis destroyer and Sea Hawk helicopters, a Defence Ministry spokesman said.

"It is designed to enhance operational ability and bolster the two allies' joint defence capacity," the spokesman said.

The drill was a prelude to the eight-week annual Foal Eagle exercise that kicks off on Monday and involves air, ground and naval field training, with around 200,000 Korean and 3,700 US troops. A week-long, largely computer-simulated joint exercise, Key Resolve, also gets underway on Monday.

The annual drills are a perennial source of tension on the divided Korean peninsula.

Seoul and Washington insist they are defensive in nature, but they are regularly condemned by Pyongyang as provocative rehearsals for invasion.

Pyongyang had offered a moratorium on nuclear testing if this year's joint drills were cancelled - a proposal rejected by Washington as an "implicit threat" to carry out a fourth nuclear test.

On Tuesday, North Korea's ruling communist party newspaper, Rodong Sinmun, said Seoul and Washington's decision to go ahead with the exercises had effectively "scuppered" any chance of resuming a dialogue with Pyongyang.

"What remains to be done is to militarily react to the US while bolstering up war deterrence to the maximum," the newspaper said.