North Korea has sent more than 100 KN-23 and KN-24 short-range nuclear capable ballistic missiles to Russia, according to Ukraine's Defense Intelligence.
Pyongyang joined the fray in August and is reinforcing Moscow's troops in Kursk after Kyiv launched an incursion in the summer. North Korea's support has become a key, as Pyongyang assists Moscow in replenishing its weapons stockpiles.
"The aggressor state of Russia has received more than 100 such missiles from the DPRK. The enemy first used these weapons in the war against Ukraine at the end of 2023," said the Defense Intelligence of Ukraine.
"Along with the missiles, Pyongyang then sent its military specialists to Russia to service the launchers and participate in war crimes against Ukraine."
Newsweek has contacted the Russian defense ministry for comment.
The KN-23 and KN-24, capable of carrying nuclear warheads, were developed by North Korea as short-range ballistic missiles, and are variants of the Hwasong-11 missile.
This shipment is part of a broader effort by North Korea to support Russia's war efforts in Ukraine, including other military supplies such as artillery systems and rocket launchers.
According to South Korea's national intelligence service, North Korea has delivered over 13,000 containers of artillery, missiles, and other conventional weapons to Russia since August, 2023.
It comes as Reuters reports North Korea is expanding a weapons-manufacturing complex that assembles short-range missiles used by Russia.
Speaking on the growing cooperation between Russia and North Korea, Associate Fellow of London-based think tank The Royal United Services Institute's (RUSI), Samuel Cranny-Evans told Newsweek: "The relationship between Russia and North Korea is clearly developing into a much closer one with various aspects and shared goals."
In April, the British arms watchdog Conflict Arms Research reported that it had examined 290 components from a North Korean missile used by Russia in an attack on Ukraine. The analysis indicated that the missile was likely a North Korean short-range ballistic missile, either the KN-23 or KN-24.
At the time, the watchdog also noted that it had identified parts from companies based in the U.S., China, Germany, Japan, the Netherlands, Singapore, Switzerland, and Taiwan.
North Korea has recently carried out a series of missile tests, which the U.S. has denounced as breaches of United Nations resolutions.
In mid-December, North Korea fired an intercontinental ballistic missile (ICBM) into the East Sea, also known as the Sea of Japan.
Meanwhile, Russia warned South Korea against sending arms to Ukraine, with Deputy Foreign Minister Andrey Rudenko calling on Seoul to "soberly assess the situation and refrain from reckless steps."
According to the Financial Times, South Korea's President Yoon Suk Yeol is considering sending arms to Ukraine in response to North Korea dispatching troops to Russia.
In October, South Korea warned that it would reconsider its stance if Russia went ahead with plans to deploy North Korean troops in its war against Ukraine. This warning was seen as an attempt to stop Moscow from escalating military ties with Pyongyang, but it has not deterred Russia.
South Korea, Ukraine, and the United States have reported that North Korean leader Kim Jong Un has sent thousands of troops to reinforce Russian forces in Kursk. Earlier this month, the Pentagon indicated that more than 10,000 are probably stationed in the Russian border area, where Ukrainian forces have maintained control since beginning their counteroffensive in August.