WASHINGTON (AP) — The Pentagon says the U.S. military sent two F-22 stealth fighter jets to take part in the annual U.S.-South Korean military trills.

A spokesman says it's the fourth time the F-22s have been deployed to South Korea. He says their participation in the exercises is meant to show U.S. commitment to the defense of South Korea and to the region.

It's the latest conspicuous display of U.S. firepower in the region. Last week, U.S. officials said two B-2 stealth bombers flew from the United States and dropped dummy munitions on a South Korean island as part of the drills -- which North Korea says are part of the preparations for an invasion.

Hours later, North Korea's Kim Jong Un ordered his generals to put rockets on standby, and threatened to strike American targets if provoked.