North Korea test fired a submarine-based ballistic missile (SLBM) from its east coast on Wednesday, CNN reports quoting South Korean authorities.
The missile flew about 500 kilometres before splashing into the Sea of Japan — the first missile of its kind to reach such a distance.
The launch took place at 5:30 a.m. local time, according to a statement from the South Korean Foreign Ministry.
The South Korean government and experts said the launch showed technical progress in the North's SLBM program.
Having the ability to fire a missile from a submarine could help North Korea evade a new anti-missile system planned for South Korea and pose a threat even if nuclear-armed North Korea's land-based arsenal was destroyed, experts said.
The North's official KCNA news agency said: "A test-fire of strategic submarine-launched ballistic missile was successfully conducted under the guidance of supreme commander of the Korean People's Army (KPA) Kim Jong-un.
The U.S. mainland and its "operational theater in the Pacific" are now within North Korea's "striking range," KCNA quoted Kim as saying.