Large US military air exercise draws warning of 'nuclear war' from North Korea The U.S. is participating in a joint exercise with South Korea.

 -- North Korea issued a dire warning Monday as a large-scale joint U.S.-South Korean air exercise got underway.

Two hundred and thirty U.S. military aircraft and 12,000 American personnel are participating in a five-day annual joint exercise with the South Korean military known as Vigilant Ace 18.

The exercise was scheduled long in advance but comes at a time of heightened tensions on the Korean peninsula and just a week after North Korea's latest intercontinental ballistic missile test reached its highest altitude yet.

“U.S. Air Force, Marine Corps, and Navy personnel will train with air assets from the Republic of Korea, flying 230 aircraft at eight U.S. and ROK military installations,” read a statement from the U.S. Air Force’s Pacific Air Forces Command issued in advance of the long-scheduled exercise. “VIGILANT ACE is part of a continuous exercise program designed to enhance readiness and operational capability of U.S. and ROK forces.”

The statement continued: "This realistic air combat exercise is designed to enhance interoperability between U.S. and Republic of Korea forces and increase the combat effectiveness of both nations."

Annual joint exercises conducted by the U.S. and South Korea routinely draw harsh criticism from North Korea’s state-run media and Vigilant Ace is no different, with North Korean media described the exercise as pushing the U.S. and North Korea "to the brink of nuclear war."

About 200 of the American aircraft participating in the exercise are permanently based on the Korean peninsula but additional aircraft and personnel are deployed to South Korea to augment those forces.

For this year’s exercise, 24 U.S. aircraft with stealth capabilities have been deployed to South Korea to participate in the exercise, including six F-22 Raptors and 18 F-35 Lightning IIs. It is commonly believed that the radar-evading stealth aircraft could be used to great effect for missions into North Korea if needed.

The stealth aircraft will fly alongside American F-16s, F-15s and F-18 Hornets, as well as South Korean military aircraft, in a realistic air combat training designed to improve coordination between both militaries.

The 28,500 American troops in South Korea routinely participate in joint military exercises with the South Korean military throughout the year.