North Korean leader Kim Jong-un, center, speaks during his visit to O Jin U Artillery Academy on Sept. 6, in this image provided by the North's official Korean Central News Agency. Yonhap

North Korean leader Kim Jong-un emphasised the importance of strengthening naval power during a tour of a naval base construction site, state media KCNA reported on Sunday.

"Now that we are soon to possess large surface warships and submarines which cannot be anchored by the existing facilities for mooring warships, the construction of a naval base for running the latest large warships has become a pressing task," Kim said.

During the tour, Kim stressed the need to build a naval port capable of operating weapons systems of the warships and revealed military measures to deploy anti-aircraft and coastal-defence systems for defending the port, according to the report.

Kim said there were geopolitical advantages of the site as a strategic vantage for the country bounded on the east and west sides by the sea. The location of the site was not specified in the report.

A recent satellite imagery analysis by 38 North indicated that North Korea's newest ballistic missile class submarine (SSB), the "Sinpo-C" class, was undergoing an extensive fitting-out period at the Sinpho South Shipyard.

In a separate visit to a shipyard, Kim ordered to increase national investments in shipbuilding projects so that immediate tasks and long-term plans for laying the foundation for the development of the shipbuilding industry are pushed forward as scheduled.

KCNA also reported on Sunday Kim's visit to a defence industrial enterprise, where he stressed the need to make munitions production more scientific and modernised to guarantee the performance of newly-developed military hardware, and an inspection of an artillery academy. (Reuters)