A squadron of U.S. stealth fighter jets arrived in South Korea on Saturday and Sunday to participate in the largest-ever joint drill this week.
A total of 24 F-22 Raptor and F-35A stealth fighters are to take part in the drill, which is dubbed "Vigilant Ace" and comes hard on the heels of North Korea's latest test on an intercontinental ballistic missile last month.
Some 230 South Korean and U.S. aircraft will practice striking North Korea's nuclear and missile bases, mobile missile launchers and long-range artillery.
A military source said the exercise had been planned well before the North's launch of a Hwasong-15 missile. "But it will be more intense because of the launch," the source added.
The Defense Ministry said the purpose of the drill is to improve the joint capability of carrying out missions in all weathers, day and night.
Other U.S. jets taking part are F-22s, F-35As, EA-18G Growler electronic warfare aircraft, F-15C fighters, and F-16 fighters, which have already been deployed at air bases here.
Twelve F-35B stealth fighters and E-3 early warning and control aircraft, and a fleet of B-1B Lancer bombers will fly from U.S. air bases in Japan and Guam.
A North Korean Foreign Ministry spokesman in a statement on Saturday denounced the exercise. It said the Trump administration is "begging for a nuclear war" and engaged in "dangerous nuclear gambling" on the Korean Peninsula.