Seoul (AFP) - North Korea has test-fired a new "ultra-precision" intelligent rocket to be deployed across its navy, state media said Saturday, in the latest evidence that Pyongyang is stepping up its development of missile technology.

The exercise was carried out by the North's East Sea fleet under the watchful eye of leader Kim Jong-Un, Pyongyang's official Korean Central News Agency (KCNA) reported.

"The ultra-precision anti-ship rocket blasted off from a rocket boat. The intelligent rocket precisely sought, tracked and hit the 'enemy' ship after taking a safe flight," KCNA said, without giving a location or date.

The new anti-ship rocket would be deployed across North Korea's navy "before long", it added.

Satisfied with the "perfect" development of the new rocket, Kim called for the production of "more tactical guided weapons of high precision and intelligence".

The nuclear-armed communist country has pushed for the development of new ballistic missiles and rockets, despite heavy sanctions imposed by the international community.

Pyongyang's rhetoric has become increasingly bellicose since the UN passed a resolution condemning North Korea's human rights record and calling for its leaders to be investigated for crimes against humanity, and Washington blamed it for a cyber attack on a US film company.

South Korea and American experts believe the North could be on the way to developing missiles that could threaten the US mainland, although opinion is split on how much progress it has made.

In 2012, Pyongyang demonstrated its rocket capabilities by sending a satellite into orbit, but it has yet to conduct a test that proves it has mastered the technology required for an effective inter-continental ballistic missile (ICBM).

South Korea's defence ministry in January said the North had already made "significant" steps in developing technology that would allow it to equip such a missile with a bomb.

The same month, the US-Korea Institute at Johns Hopkins University released satellite images that offered fresh evidence North Korea is developing a marine-based missile system that would allow it to strike back if hit by a nuclear attack.

Commercial satellite pictures suggested a new North Korean submarine -- first seen in July last year -- housed one or two vertical launch tubes used to fire either ballistic or cruise missiles, the think-tank said.

Development of a submarine-launched missile capability would take the North Korean nuclear threat to a new level, allowing deployment far beyond the Korean peninsula.