North Korea on March 8 released images of leader Kim Jong-un inspecting the construction of what it calls a “nuclear-powered strategic guided missile submarine,” marking its first public acknowledgment of the project.

North Korea has conducted a slew of underwater-launched ballistic missile tests since 2016, but all launches were made from the same 2,000-tonne-class submarine which has a single launch tube. Many experts call it a test platform, rather than an operational submarine in active service.

North Korea has released the first images of its under-construction nuclear-powered submarine, which is likely being built with assistance from Russia. The nuclear-powered submarine can pose a major threat to Pyongyang’s immediate neighbor,