North Korea says longest test launch was latest Hwasong-18 ICBM

North Korea tested its latest Hwasong-18 intercontinental ballistic missile (ICBM) on Wednesday, its state media reported, saying the weapon is the core of its nuclear strike force and a warning to the US and other adversaries.

The launch, reported at the time by militaries in South Korea and Japan, was condemned by the US and leaders in Seoul and Tokyo, among others.

The United Nations Security Council, which has passed resolutions banning North Korea's ballistic missile and nuclear weapons development, will meet publicly on Thursday to discuss the missile launch.

The Hwasong-18 was first flown in April. It is the North's first ICBM to use solid propellants, which can allow faster deployment of missiles during a war.

"The test-fire is an essential process aimed at further developing the strategic nuclear force of the Republic and, at the same time, serves as a strong practical warning" to adversaries, state news agency KCNA said.

Accusing Washington of increasing tensions by deploying submarines and bombers to the Korean peninsula and conducting nuclear war planning with South Korean allies, KCNA said the military security situation "has reached the phase of nuclear crisis beyond the Cold War era."

North Korean leader Kim Jong Un oversaw the test, and said the country would take increasingly strong measures to protect itself until the US and its allies drop their hostile policies, the report said.

It is "remarkable" that both of North Korea's Hwasong-18 tests to date appear to have been complete successes despite the country’s lack of experience with other large, multi-stage solid-propellant missiles, Ankit Panda, a senior fellow at the US-based Carnegie Endowment for International Peace, said in a report for the Seoul-based NK PRO, which monitors North Korea.

"Just how North Korea has managed to attain this stunning level of success with its solid-propellant ICBM remains a mystery, but Kim Jong Un will have few complaints," Panda wrote.

The Hwasong-18's 74-minute flight time was the longest ever for a North Korean missile test, KCNA said, adding the second and third stages were flown on a lofted trajectory to a high altitude for safety.

"The test-fire had no negative effect on the security of the neighbouring countries," it said.

North Korea said the missile flew 1,001km to an altitude of 6,648km.

Japan said the missile landed in the sea east of the Korean peninsula and about 250km west of northern Japan's Okushiri island.

Japan’s defence ministry said four of its F-2 jets and two US Air Force F-15C jets conducted a joint air drills west of Kyushu island on Wednesday to counter “intensifying national security environments” including North Korea’s ICBM launch.

Photos released by KCNA showed the Hwasong-18 being launched from a cannister mounted on a road-mobile, multi-wheeled vehicle known as a transporter erector launcher (TEL), designed to allow missiles to be fired from unpredictable locations.

Colin Zwirko, senior analytic correspondent for NK PRO, noted, however, that Wednesday's launch occurred from the same spot outside Pyongyang as the Hwasong-18's first test, in a field that commercial satellite imagery showed had been purpose built and likely reinforced with concrete beneath the grass.

In footage aired by the state broadcaster, dramatic music played and a voice counted down to the launch as the missile rose on smoke and flame from the camouflaged launcher.