The US Treasury said Ashot Mkrtychev, 56, of Bratislava, was involved in arranging sales and barter deals for North Korea to ship "over two dozen" kinds of weapons and munitions to Russia between late 2022 and early 2023.

In exchange, the Treasury said, Pyongyang would obtain cash, commercial aircraft, commodities and raw materials.

Mkrtychev worked with officials from both sides to makes the deals happen, according to the Treasury.

But it did not say if any were completed, or detail the specific weapons involved.

Last September the White House said Russia was buying artillery shells and rockets from North Korea, a claim denied by Pyongyang.

Then in November, White House national security spokesman John Kirby said North Korea was shipping the ammunition to Russia but obfuscating the trade by making it look like it was sending the arms to the Middle East or North Africa.

Weeks later Kirby said North Korea completed an initial arms delivery to the semi-independent Russian military force, the Wagner Group, which is fighting on the front lines in Ukraine.

Pyongyang again denied the US claim.

Mkrtychev was placed on the US Treasury's sanctions blacklist, which bans Americans or businesses like banks that have American branches of having any dealings with him.

"We remain committed to degrading Russia's military-industrial capabilities, as well as exposing and countering Russian attempts to evade sanctions and obtain military equipment from (North Korea) or any other state that is prepared to support its war in Ukraine," said Treasury Secretary Janet Yellen in a statement.