Japan's Kyodo News reports two warships from Japan's Maritime Self-Defense Forces have left the U.S. Navy base in Sasebo, Nagasaki Prefecture.

Citing a Japanese Defense Ministry official, the report said the warships left Friday to join an exercise with the USS Carl Vinson aircraft carrier, which is headed toward the Korean Peninsula.

Kyodo said the drill is believed to be a show of force designed to deter North Korea from conducting further missile and nuclear tests. The official said the exact time and location of the drill have not yet been determined.

Joint drills involving the USS Carl Vinson and Japanese Navy destroyers were held in early and late March in the East China Sea.