North Korean leader Kim Jong-un visited a front-line military detachment in the East Sea and instructed firing drills, its official media said Monday.

The young leader "inspected the defense detachment on Ung Islet ... which is defending an outpost in the East Sea of Korea," the North's state-run Korean Central News Agency (KCNA) said in an English dispatch, without disclosing the date of the visit, as it often does.

The islet is located in waters off its eastern border town of Wonsan, Gangwon Province, and not far from Ryo Islet, where the leader visited last month.  

Stressing "the need for the service personnel of the detachment to turn the Ung Islet into an impregnable fortress," Kim guided drills of the service personnel of the detachment and then "greatly satisfied to see them accurately hit the target," it added.

Kim also watched a heavy gymnastic drill and set forth "important tasks which would serve as guidelines for rounding off the combat capability of the detachment."

Underlining the need to "always direct efforts to the anti-U.S. education and class education," Kim instructed commanding officers there to send enemies intruding into its waters "to the bottom of the sea to the last man" in case of a battle, according to the KCNA.

Kim was accompanied by military officers, including the Korean People's Army (KPA) Vice Marshal Hwang Pyong-so and Colonel General Pak Jong-chon, it said. (Yonhap)