Japan, the United States and South Korea have staged joint aerial drills, after North Korea said it fired a new intercontinental ballistic missile on Thursday.
The South Korean Joint Chiefs of Staff announced on Sunday that the exercises took place in airspace east of the country's southern island of Jeju.
The military said the practice sessions confirmed the ability to accurately attack simulated targets.
The maneuvers reportedly involved US F-16 fighter jets and at least one B-1 bomber. The North is wary of the plane's capabilities.
South Korea's Yonhap News Agency reported that the B-1 is capable of dropping many bombs and reaching the Korean Peninsula from the US Air Force base in Guam in about two hours.
The South Korean military says the three countries will strengthen coordination to deter and jointly respond to the North's threats.
Speculation is growing that Pyongyang could fire more ballistic missiles and conduct a nuclear test to coincide with the US presidential election due on November 5.