WASHINGTON (AP) — The Air Force says it cost $2.1 million to send two nuclear-capable B-2 bombers on a training exercise over South Korea that was widely viewed as a show of force in response to weeks of threats from North Korea.

The service’s Global Strike Command said Friday in a statement that the total flight time for the B-2s was 75 hours. The aircraft made the more than 6,500-mile round trip from Whiteman Air Force Base in Missouri to a South Korean island range on Thursday.