North Korea's national media, KCNA confirmed the test launch of new smaller, submarine ballistic missiles. 

The news came a day after the South Korean military said that the launch had taken place on the North Korean East Coast.

According to North Korea's state news agency KCNA, the "new-type" SLBM was launched from the same submarine which participated in a 2016 test of an earlier SLBM.

Despite having a huge fleet of aging submarines, North Korea has not yet deployed the operational ballistic missile submarines beyond the experimental Gorae-class vessel used in the tests.

The new SLBM, according to KCNA, has improved capabilities like "flank mobility and glide skip mobility."

"(The SLBM) will make a significant contribution to raising the country's defense technology and strengthening our navy's underwater operating capabilities," KCNA stated.

According to the Joint Chiefs of Staff of South Korea, the missile was fired from the waters near Sinpo, where North Korea stores submarines and equipment for test-launching SLBMs.