The USS Ronald Reagan aircraft carrier was conducting joint exercises with a Maritime Self-Defense Force destroyer in the waters near Okinawa on Wednesday, the two countries' militaries said, amid rising tensions with North Korea.

The exercises involving the two allies are the latest in a string of joint drills held amid a spate of missile launches — including two over Japan — by nuclear-armed North.

The drills came on the heels of an exercise a day earlier that saw U.S. Air Force B-1B heavy bombers from Guam link up with their Japanese and South Korean counterparts for bilateral missions. The U.S.-South Korean show of force saw the two militaries conduct a missile drill off the South's eastern and western coasts, flying over the Korean Peninsula in the process.