The USS Ronald Reagan, plus a cruiser and two destroyers, will join tens of thousands of US and South Korean soldiers in the exercises, which the allies say are purely defensive in nature.

The communist state routinely protests at the annual drills, which it calls a preparation for invasion.

"These are very dangerous provocations casting a shadow over the implementation of an agreement adopted with much effort at the six-party talks on February 13 and the progress of the talks," said a North Korean foreign ministry spokesman.

"Dialogue and sabre-rattling cannot go together. The US and South Korean warlike forces will be wholly responsible for all the adverse consequences to be entailed by their provocative military actions," said the spokesman quoted by the official Korean Central News Agency.

The North agreed at six-party talks on February 13 to scrap its nuclear programmes in return for economic aid and diplomatic benefits. But the latest six-party round remained deadlocked Thursday in a dispute about the repayment of North Korean funds which had been frozen in a Macau bank.

The US military says the week-long exercises starting Sunday, RSOI (Reception, Staging, Onward Movement and Integration) and Foal Eagle, are purely designed to test the ability of allied forces to defend South Korea against attack and to receive reinforcements from overseas.

The US forces say they have told North Korea that "this is a defensive military readiness exercise, and that it is not meant to be provocative in any way."

The US has stationed tens of thousands of troops in the South since the Korean war began in June 1950 with an invasion by the North.

Currently some 29,500 US troops are stationed here to help 680,000 South Korean forces face up to North Korea's 1.1-million-strong military.

The carrier group's visit to South Korea and involvement in the drills "is a sign of the depth of commitment on the part of the US to the peace and security and stability of the Korean peninsula and the region," said Rear Admiral Charlie Martoglio, commander of the carrier group.

The USS Ronald Reagan commander, Captain Terry Kraft, declined to give details of the exercises during a visit Wednesday by journalists to the ship.

But he said his ship will "be exercising a broad range of missions."

The carrier, commissioned in July 2003, is almost as long as the Empire State Building is tall (more than 330 metres or 1,090 feet) and carries more than 5,000 crew.

Its two nuclear reactors give it a top speed of more than 30 knots. Its air wing includes the F18 Super Hornet, the F18 Sea Hornet, EA6B Prowler radar-jamming aircraft, E-2C Hawkeye airborne early warning aircraft and helicopters.