"The KPA (North Korea's army) will actively put into practice its earlier statement that it will do all it can to round off the powerful striking means to cope with the large-scale war manoeuvres," the North Korean army said in a statement.

The statement, carried by the English service of Pyongyang's official Korean Central News Agency, did not elaborate on the likely response.

"The US will be held wholly responsible for the catastrophic impact the above-said sabre-rattling will have on the implementation of the February 13 agreement and the six-party talks," it said, referring to a nuclear disarmament deal.

The statement was handed over to the US-led United Nations Command at a colonel-level meeting at Panmunjom on the inter-Korean border, it said.

The annual drill, held this year from August 20-31, will coincide with a planned inter-Korean summit from August 28-30 in Pyongyang.

Unification Minister Lee Jae-Joung told parliament Friday the Seoul government would discuss "an appropriate response" if Pyongyang officially demands the exercise be scrapped or postponed.

The North's state bodies have denounced the military exercise as an "intolerable act of provocation."

About 10,000 US troops and an undisclosed number of South Korean soldiers will take part in the Ulchi Focus Lens exercise, which involves a major computer-simulated war game on how to respond to an invasion of the South.

North Korea routinely denounces such drills as a prelude to an attack against it. The United States insists the exercise is purely defensive.

In February the two Koreas, the United States, China, Russia and Japan reached a deal for energy-starved North Korea to receive one million tons of fuel oil or equivalent aid, and diplomatic concessions, in return for scrapping its nuclear weapons programmes.

In response, the North shut down its main nuclear reactor complex last month -- its first commitment under the agreement.