North Korea says it has successfully tested a submarine-launched missile, which if confirmed would be a significant boost in its arsenal.

Analysts say North Korea has several nuclear warheads but this development would be an advance as submarine-fired devices are difficult to detect.

This latest test, according to BBC, has not been independently verified.

The US said using ballistic missiles was a “clear violation” of UN sanctions against North Korea.

A statement from the State Department made no comment on the reported test but called on North Korea “to refrain from actions that further raise tensions in the region”.

State media described the missile emerging with “a fiery, blazing trail”, but did not mention the date or the location of the test.

The North Korean leader, Kim Jong-un, was pictured apparently overseeing the launch.

Mr Kim said his country now possessed a “world-level strategic weapon capable of striking and wiping out in any waters the hostile forces infringing upon (North Korea’s) sovereignty and dignity”, the reports said.

After the announcement, South Korea said the North fired three anti-ship cruise missiles into the sea off its east coast.

Pyongyang had warned it would fire without warning against vessels it claims have violated its waters.

South Korea is yet to comment on the missile test, but the country’s National Security Council has met in emergency session.