Two Air Force B-1 Lancer bombers fly alongside Japan Air Self-Defense Force fighers over the Sea of Japan, also known as the East Sea, Wednesday, Aug. 30, 2023. (Japan Air Self-Defense Force)

YOKOTA AIR BASE, Japan — U.S. Air Force B-1 Lancer bombers flew with Japanese F-2 and F-15 fighters Wednesday over the Sea of Japan to demonstrate their ability to respond quickly to threats in the region, according to a U.S. Forces Japan.

Bombers are just one of the deterrence options readily available to the U.S.-Japan alliance, the command said in a statement that day.

“Two B-1 Lancer bombers with the U.S. Air Force integrated with eight Japan Air Self-Defense Force F-2 fighter aircraft and four F-15 fighter aircraft, exemplifying our alliance's ability to quickly and decisively respond to threats against Japan and the region,” the statement said.

In the past, U.S. bombers have followed up similar missions by moving to South Korea to train with that country’s fighters. It was unclear whether this was the case with Wednesday’s exercise, though it coincided with Ulchi Freedom Shield, a series of drills involving U.S. and South Korean forces that kicked off Aug. 21 and conclude Thursday.

In a Monday speech marking North Korea’s Navy Day, leader Kim Jong Un said “the danger of a nuclear war” has made the region unstable because of U.S.-led hostilities, according to the state-run Korean Central News Agency.

Kim cited the ongoing drills, the deployment of powerful U.S. weapons to the peninsula and a recent trilateral summit in which the U.S., South Korea and Japan agreed to boost defense cooperation to counter the North’s nuclear program.

U.S. Forces Korea and South Korea’s Ministry of National Defense describe the drills as routine, defensive training; South Korean Joint Chiefs of Staff spokesman Col. Lee Sung-jun also described them as a means “to counter the advancing threats from North Korea.”