North Korea says it successfully tested new solid-fuel intercontinental ballistic missile

North Korea said Friday it had successfully tested a solid-fuel intercontinental ballistic missile, which state media hailed as a key breakthrough for the country's nuclear counterattack capabilities.

South Korea's military said Thursday that the North had likely tested a new type of ballistic missile, with the launch briefly triggering an evacuation order in parts of Japan.

Photographs released by state media showed leader Kim Jong Un -- accompanied by his young daughter -- watching a black-and-white missile blast off in a cloud of smoke, and smiling in jubilation after the purportedly successful launch.

"A new type of intercontinental ballistic missile 'Hwasung-18' was test fired on Thursday as the key means of strategic military force," the official Korean Central News Agency (KCNA) said.

"The purpose of the test launch was to confirm the performance of the high-power solid-fuel multi-stage engines, the stage separation technology and the reliability of the control systems with different functions, and to evaluate the military effectiveness of the new strategic weapons system," it added.

Kim said the new weapon "will greatly reorganise our strategic deterrence and reinforce effectiveness of our nuclear counterattack," according to KCNA.

"We will strike with deadly force and respond aggressively until the enemy gives up its idle strategy and foolish behaviour and so that it will suffer in endless fear," he added.

All of Pyongyang's known intercontinental ballistic missiles are liquid-fuelled, and solid-fuel ICBMs that can be launched from land or submarines have long been at the top of Kim's wish list.

Such missiles are easier to store and transport, more stable and quicker to prepare for launch, and thus harder to detect and destroy pre-emptively.

At a military parade in Pyongyang in February, North Korea showed off a record number of nuclear and intercontinental ballistic missiles, including what analysts said was possibly a new solid-fuel ICBM.

North Korea has "repeated again its pattern of provocation with its new weapons," Go Myong-hyun, researcher at the Asan Institute for Policy Studies, told AFP.

"First, it tested a solid-fuel motor before showcasing the missile at a military parade in February and now they carried out an actual test," he said.

"The reason North Korea is obsessed about solid-fuel missiles is because it will significantly reduce the preparation time before launch," Go said.

"This is important as the longer it takes after bringing out the missile from a silo or a tunnel, the higher the possibility of destruction before launch."

The announcement comes a day before North Korea is set to mark one of its most important political anniversaries, the Day of the Sun on April 15.

The date commemorates founding leader Kim Il Sung's birth anniversary and has typically been celebrated with significant weapons tests or military parades.

Relations between the two Koreas are at one of their lowest points in years, with Pyongyang declaring itself an "irreversible" nuclear power last year, effectively ending the possibility of denuclearisation talks.

Kim also ordered the military this year to intensify drills to prepare for a "real war".

Washington and Seoul have ramped up defence cooperation in response, staging joint military exercises with advanced stealth jets and high-profile US strategic assets.

North Korea views such exercises as rehearsals for invasion and described them on Tuesday as "frantic" drills "simulating an all-out war against" Pyongyang.