N Korea aggressively working on ballistic missile sub, says report

Satellite images taken this month of a North Korean naval shipyard indicate Pyongyang is pursuing an "aggressive schedule" to build its first operational ballistic missile submarine, a US institute reported on Thursday.

Washington-based 38 North, a North Korea monitoring project, cited images were taken on November 5 showing activity at North Korea's Sinpo South Shipyard.

"The presence of what appear to be sections of a submarine's pressure hull in the yards suggests construction of a new submarine, possibly the SINPO-C ballistic missile submarine - the follow-on to the current SINPO-class experimental ballistic missile submarine," 38 North said in a report.

The report said that throughout this year there had been a continued movement of parts and components into and out of two parts yards adjacent to the constructions halls in the centre of the shipyard.

It said the November 5 images showed two large circular objects that could be sections of a submarine's pressure hull. It said these appeared larger than those for North Korea's ROMEO-class attack submarine.

Images of a test stand indicated continued testing of a mechanism for ejection launch of missiles from a submarine. However, the report said no activity could be seen suggesting preparations for a new test of a submarine-launched missile.

North Korea has been working to develop a nuclear-tipped missile capable of reaching the United States, sparking a major international crisis in which US President Donald Trump has said that all options are under consideration, including military ones.

North Korea is also thought to be working on a solid-fuel missile for submarine launches.