Kim visited shipyards focused on building warships, the Korean Central News Agency reported, without giving details of the exact date or location of the inspection.
Kim "learned about the building of a nuclear-powered strategic guided missile submarine," the report said, which was one of Kim's key military goals on a laundry list of high-tech weaponry unveiled at a previous party congress.
The report is likely referring to a nuclear-powered submarine capable of launching ballistic missiles, Yonhap news agency reported, adding this was the first time the nuclear-armed North had revealed construction of a ballistic missile submarine.
Kim said the country's "sea defense capability... will be fully displayed in any necessary waters without limitation," KCNA said.
"The development of the naval force into an elite and nuclear-armed force constitutes an important content in the strategy for the development of the national defense," it added.
MA/PR