North Korea has reportedly conducted a third test of a new submarine-launched ballistic missile (SLBM) from an underwater test platform near the country's coastal city of Sinpo.
US defence officials stated that this new development is part of North Korea's efforts to expand the country's nuclear weapon capacity.
Previous tests of the KN-11 missile were conducted in January and October 2014. The first test was carried out onboad a sea-based platform, while the second test was launched from a land-based static platform.
According to analysts, these tests indicate that developing advanced underwater nuclear strike capabilities, is a high-priority project for North Korea.
North Korea is reportedly developing the new missile at its Sinpo South Shipyard.
Pentagon spokesman lieutenant colonel Jeffrey Pool declined to comment on this, saying that the details of the test are classified.
Former Defence Intelligence Agency official Bruce Bechtol Jr said: "The submarine can get the platform to launch the missile within range of the continental United States, Alaska, or Hawaii.
"Thus, once operational, this immediately brings key nodes in the United States within range of what would likely be a nuclear armed missile."
The new missiles are expected to join a series of strategic nuclear delivery vehicles available to its military.
North Korea reportedly possesses 78 submarines, the most in the world, followed by the US, China and Russia. However, most of the country's ships are outdated Soviet-era and Chinese vessels.