North Korea is warning this week's large-scale military exercises between the United States and South Korea could damage diplomatic efforts to end the North's nuclear weapons programs. VOA's Kurt Achin reports from the USS Nimitz aircraft carrier, where U.S. Navy pilots are supporting the annual military drills with round-the-clock flight missions.

One after another, U.S. F-18 fighter jets soared from the deck of the USS Nimitz aircraft carrier, catapulting from a total standstill to speeds of about 300 kilometers an hour in just three seconds.

The maneuvers, taking place all week in waters east of the South Korean city of Busan, are part of the annual military drill named "Key Resolve." As they do every year, U.S. and South Korean forces are fine-tuning their cooperation in defending South Korea against a potential North Korean attack.

North Korea invaded the South in 1950. An armistice was signed three years later, but there was never a formal peace treaty to conclude the conflict.

On Monday, the communist North repeated its condemnation of the exercises, which it views as aggressive. The North's official news agency quoted a Foreign Ministry official in Pyongyang as saying the maneuvers "will only put a brake on the process of the denuclearization of the Korean Peninsula."

Pyongyang is already three months overdue in providing a declaration of its nuclear activities it promised to produce by the end of 2007. The declaration is part of a broader deal to trade financial aid and diplomatic incentives for the North's gradual elimination of its nuclear arsenal.

U.S. officials reject accusations this week's drills are offensive in nature. Rear Admiral Terence Blake, commander of the Nimitz strike group, says the vessels' mission is the same wherever it is deployed.

"To promote peace, stability, prosperity, in any region it [Nimitz] goes into. That is our goal," he said. "When we go out and we do these exercises the idea behind the exercises is to promote those three concepts. That is it."

North Korea conducted its first nuclear test in October 2006. As it has done frequently in the past, North Korean media said the U.S. military drills may lead it to bolster what Pyongyang calls its nuclear "deterrent."