By Hyunsu Yim, Josh Smith and Hyun Young Yi

SEOUL (Reuters) -North Korea flexed its military muscle with the test of a huge new solid-fuel intercontinental ballistic missile dubbed Hwasong-19, state media said on Friday, amid international uproar over its troops deployed to aid Russia in Ukraine.

The launch on Thursday flew higher than any previous North Korean missile, according to the North as well as militaries in South Korea and Japan that tracked its flight deep into space before it splashed down in the ocean between Japan and Russia.

State news agency KCNA lauded it as “the world’s strongest strategic missile”.

While questions remain over North Korea’s ability to guide such a missile and protect a nuclear warhead as it reenters the atmosphere, the Hwasong-19, like North Korea’s other latest ICBMs, demonstrated the range to strike nearly anywhere in the United States.

“The new-type ICBM proved before the world that the hegemonic position we have secured in the development and manufacture of nuclear delivery means of the same kind is absolutely irreversible,” North Korean leader Kim Jong Un said while overseeing the launch, KCNA reported.

The launch, days before Tuesday’s U.S. presidential election, drew swift condemnation from Washington and its allies in South Korea, Japan and Europe, as well as the United Nations secretary-general.

“The missile continues to underwrite the growing credibility of North Korea’s strategic deterrent capabilities,” said Ankit Panda, a senior fellow at the U.S.-based Carnegie Endowment for International Peace, adding that Kim appeared specifically interested in communicating that message to the United States.

PYONGYANG-MOSCOW TIES

A spokesperson for South Korea’s unification ministry, which handles relations with the North, said the launch could have been for several purposes, including demonstrating military technology, pressuring Washington and diverting attention from the issue of sending North Korean troops to Russia.

Ukraine’s President Volodymyr Zelenskiy blasted what he called his allies’ “zero” response to Russia’s deployment of North Korean troops for the war in Ukraine, which has also sparked worries that Moscow could provide sensitive military technology to Pyongyang in return.

Russia and North Korea have not denied the troop deployments and have defended their right to help each other.

U.S. Defense Secretary Lloyd Austin said the Pentagon was very early in its assessment phase of the missile launch “and we don’t see any indication at this point that there was Russian involvement.”

KCNA said the launch did not affect the safety of neighbouring countries and was an appropriate military step in the face of threats from North Korea’s enemies.

Although Russia may provide some specialists to assist with inspections or modifications, Kim Dong-yup of the University of North Korean Studies in Seoul expressed scepticism it would share sensitive technology with Pyongyang.

“Even if some level of military cooperation between North Korea and Russia is possible, they are likely to be very cautious when it comes to core military technologies.”

HEAVIER PAYLOADS

The Hwasong-19 will deploy alongside the Hwasong-18, which was first launched last year and is also powered by solid fuel, KCNA said.

Solid-fuel missiles do not need to be fuelled immediately ahead of launch, are often easier and safer to operate and require less logistical support than liquid-fuel weapons.

“It can be stored and moved anywhere, allowing for excellent mobility, stealth and survivability,” said Kim of the University of North Korean Studies.

Photos released by KCNA showed a large, multi-stage missile launched from a canister carried by a transporter-erector-launcher vehicle. The agency showed photos from cameras that appeared to be attached to the missile, taking images of stage separations and the earth.

“The increased length likely means a greater fuel capacity, which directly affects thrust and potentially increases range,” Kim said.

But North Korea’s existing missiles already had the range to reach anywhere in the United States, and the Hwasong-19’s expanded capacity combined with larger payload section is more likely designed to be able to carry heavier, and potentially multiple, nuclear warheads, he said.

“North Korea may continue testing to see if, during the final reentry phase, the warheads can separate and each head toward individual targets,” Kim added.

The Hwasong-19 flew of 1,001.2 km (622.12 miles) for 85 minutes and 56 seconds before landing in the sea off the east coast of the Korean peninsula, with a maximum altitude of 7,687.5 km (4,776.79 miles), KCNA said.