North Korea's Foreign Ministry said that its "nuclear armed forces will exist forever as a powerful means of justice," according to state media.

North Korea’s military modernization underscores the importance of America and its own East Asian allies expanding their own submarine fleets.

North Korea has conducted a slew of underwater-launched ballistic missile tests since 2016, all from the same 2,000-tonne submarine with a single launch tube. This particular submarine has been described by experts as a test platform rather than an operational submarine in active service.