Kim made the remarks while inspecting a naval fleet berthed on the country's east coast, the official Korean Central News Agency (KCNA) reported on Monday.
Speaking aboard a warship, the country's leader vowed to reinforce the navy with "improved combat efficiency and full modern means of surface and underwater offensive and defensive" capabilities.
"We will put spurs to the modernization of naval weapons and equipment, including the building of powerful warships and the development of shipboard and underwater weapon systems," Kim was quoted as saying.
"The Navy should thoroughly keep constant mobility and steadily increase the capability for actual war, so that they can actively carry out their combat missions in the unfavorable circumstances," he added.
According to the report, during his tour of North Korea's navy warship, Kim personally oversaw a test of strategic cruise missiles.
The launch was aimed at verifying the "combat function of the ship and the feature of its missile system," while improving the sailors' capability to carry out an "attack mission in actual war," the KCNA said without giving the date of Kim's visit.
"The ship rapidly hit target without even an error," it added.
Kim touted the ship for maintaining "high mobility and mighty striking power and constant preparedness for combat to cope with sudden situations," the agency reported.
The North Korean leader's new push for the production of weapons and maintaining military preparedness came amid annual military drills by Pyongyang's archenemies, the United States and South Korea, which started on Monday. The North views such drills as rehearsals for a military invasion of its territory.
Washington and Seoul had announced last Monday that they would stage the Ulchi Freedom Guardian summer war games from August 21 to 31 to improve their ability to respond to what they described as the North's evolving nuclear and missile threats.
South Korea's military has announced that this year's exercises will be held on the "largest scale ever," including through mobilizing tens of thousands of troops from both sides, as well as some member states of the United Nations Command.
MP/PressTV