A new facility under construction near North Korea's main submarine port appears to be for submarine construction or maintenance purposes, a U.S. monitoring website said Monday, rejecting reports that the facility appears to be a bunker for larger submarines.

The IHS Jane's 360 reported last month that a fortified structure under construction some 2.25 kilometers south of the Shinpo Shipyard appears to be two covered docks or submarine pens that could shelter large ballistic missile submarines.

But the U.S. monitoring website 38 North said the assessment is inaccurate.

"While media reports have identified this new facility as submarine pens for a new large class of ballistic missile submarines under development by North Korea, that analysis is incorrect," 38 North said in a report.

"Submarine pens are typified by sea-level reinforced concrete structures similar to those built by Germany during World War II at Saint-Nazaire, France, but North Korea has not and does not employ such facilities," 38 North said. Instead, Pyongyang uses "underground berthing" facilities in which a sea-level facility is excavated from under a coastal hill, it said.

The facility under construction supports none of the characteristics of submarine pens, 38 North said.

"If and how this new facility will be associated with the GORAE-class ballistic missile submarine or future ballistic missile submarines is currently unclear," it said. "If it is to be associated with those programs, it is more likely to play a maintenance or construction role." (Yonhap)