In what’s being described as an “unprecedented” maneuver, the U.S. has dispatched four F-35B stealth jets and two B-1B strategic bombers to train with the South Korean military in exercises conducted over the Korean peninsula.

Yonhap, South Korea’s largest news agency, reports that the joint operation “staged air-to-ground precision-strike drills against the North’s core facilities over the Pilseung Range in the eastern mountainous province of Gangwon.”

This is in response to North Korea’s ballistic missile launches and their continued development of nuclear weapons, and comes just two days after the NORKs fired an intermediate-range ballistic missile over the northern Japan.

“Our Air Force has the capability of conducting perfect combined operations,” Lt. Gen. Won In-chul, commander of South Korean Air Force Operations Command. “No matter when, how and where the enemy provokes, we will perfectly retaliate to make it feel an insurmountable sense of fear and deep regret.”

U.S. Air Force officials had an equally pointed message for Pyongyang, telling Yonhap, “The U.S. did not dispatch bombers (to Korea) during the exercise in hopes that the reduced scale would send a positive signal to North Korea and the region.”