In a powerful display of military might, Japanese and South Korean warships separately trained with three U.S. aircraft carriers on Sunday as the allies presented a united front against nuclear-armed North Korea.

Japan sent its massive Ise helicopter destroyer — one of the largest warships in its fleet — as well as the Inazuma and Makinami destroyers, for the joint military exercises in the waters near the Korean Peninsula. They joined the Yokosuka, Kanagawa Prefecture-based USS Ronald Reagan and the USS Nimitz and USS Theodore Roosevelt aircraft carrier strike groups.

It was the first time the Maritime Self-Defense Force had drilled with so many carriers.