North Korea declared it will deploy the first of its largest modern class of warships in mid-June following its first extended navigation test off the west coast on Thursday, according to state media.

The Korean Central News Agency (KCNA) reported Friday that leader Kim Jong Un was aboard the No. 51 Choe Hyon destroyer for the previous day’s “maneuverability” test “over a 120-nautical-mile stretch of the West Sea.” 

It added that he discussed the ongoing construction of the third and fourth destroyers.

This is the first time Pyongyang has claimed or shown the ship navigating in the open ocean.