North Korea says U.S. threats make war unavoidable, China urges calm

A U.S. Air Force F-35A Lightning II assigned to Hill Air Force Base, Utah, conducts a training flight with F-16 Fighting Falcons assigned to Kunsan Air Base, South Korea over the city of Gunsan, in South Korea. Courtesy Josh Rosales/U.S. Air Force/Handout via REUTERS

SEOUL (Reuters) - Two U.S. B-1B heavy bombers joined large-scale combat drills over South Korea on Thursday amid warnings from North Korea that the exercises and U.S. threats have made the outbreak of war "an established fact."

The annual U.S.-South Korean "Vigilant Ace" exercises feature 230 aircraft, including some of the most advanced U.S. stealth warplanes, and come a week after North Korea tested its most powerful intercontinental ballistic missile (ICBM) to date, which it says can reach all of the United States.