Satellite images show North Korea expanding key facility making missiles Russia uses in Ukraine

The plant at Ryongsong Machine Complex in Hamhung reportedly makes Hwasong-11 solid-fuel ballistic missile

North Korea is expanding a weapons manufacturing complex that assembles a variety of short-range missiles allegedly used by Russia against Ukraine, satellite images showed.

Researchers at a think tank in the US identified the facility, known as the “February 11” plant, which is part of the Ryongsong Machine Complex in Hamhung in North Korea's second-most populous city.

The assessment comes just days after South Korea's spy agency accused Pyongyang of supplying additional artillery systems to Russia and amid claims that some of the North Korean troops deployed in Russia have begun engaging in combat.

Both Moscow and Pyongyang have denied allegations of North Korea sending weapons and munitions to aid Russia's war effort.

A satellite image shows suspected construction of worker housing near Hamhung in North Korea (REUTERS)

The North has ratified a mutual defence treaty with Russia signed in June which calls to "immediately provide military and other assistance using all available means" if either side is in a state of war.

The satellite images taken in October by Planet Labs show what seems to be an additional assembly building under construction along with a new housing facility, likely intended for workers, according to an analysis by researchers at the James Martin Center for Nonproliferation Studies (CNS).

Pyongyang appears to have improved the entrances of some of the underground facilities at the complex while constructing the new assembly building which is 60-70 per cent the size of the old one.

Sam Lair, a research associate at the CNS, told Reuters the facility is the only one known to produce the Hwasong-11 solid-fuel ballistic missile.

Ukrainian officials say these missiles, known as KN-23 in the West, have been used by Russian forces in their assault on Ukraine.

A satellite image shows a suspected missile assembly building under construction near Hamhung (REUTERS)

North Korean authorities have removed a disused bridge crane from in front of a tunnel entrance which was blocking easy access, suggesting they might be placing an emphasis on that part of the facility, according to the researcher. "We see this as a suggestion that they're massively increasing, or they're trying to significantly increase, the throughput of this factory," Mr Lair told Reuters.

North Korean state news agency KCNA has reported that construction is underway at the Ryongsong Machine Complex. The facility "is pushing ahead with the projects for attaining the goal for modernisation planned for this year," KCNA reported this month.

The work includes rebuilding production facilities as well as assembling and installing equipment in machine workshops and a steel casting workshop, it said.

In November, Russian Telegram channels posted photos purportedly showing North Korean “Koksan” 170mm self-propelled guns being moved by rail inside Russia. The Financial Times, citing Ukrainian intelligence assessments, reported that the North has sent 50 170mm self-propelled howitzers and 20 240mm multiple launch rocket systems to Russia in recent weeks.

South Korea's spy agency said last month the North had sent more than 13,000 containers carrying artillery, missiles and other conventional arms to Russia since August 2023 to replenish its dwindling weapons stockpiles.

North Korea is also claimed to have sent some 11,000 soldiers to the Kursk border region where the Russian forces have been fighting off a Ukrainian incursion since August.