Japan's navy has dispatched its largest destroyer reportedly tasked with escorting U.S. military ships off the Japanese coast amid heightened tension on the Korean Peninsula.

The helicopter carrier Izumo departed the Yokosuka port near Tokyo earlier Monday.

Japanese media say the destroyer is set to escort a U.S. supply ship in the Pacific Ocean south of Tokyo later Monday, a new mission under the new security legislation allowing Japan's military a greater role in overseas activity. The U.S. supply ship is expected to refuel other American warships, including the USS Carl Vinson strike group, currently in the region.

Japan's defense ministry only says the Izumo left to eventually participate in an international naval event in Singapore on May 15.