North Korea said on Tuesday it has never had arms dealings with Russia and has no plans to do so, its state media reported, after the United States said North Korea appears to be supplying Russia with artillery shells for its war in Ukraine.

White House National Security spokesperson John Kirby said last week the United States has information that indicates North Korea is covertly supplying Russia with a "significant" number of artillery shells.

Kirby said North Korea was attempting to obscure the shipments by funneling them through countries in the Middle East and North Africa and that Washington was monitoring to see whether the shipments are received.

A North Korean defense ministry official called the allegations a rumor and said Pyongyang has "never had 'arms dealings' with Russia" and has "no plan to do so in the future."

"We regard such moves of the U.S. as part of its hostile attempt to tarnish the image of the DPRK in the international arena by invoking the illegal 'sanctions resolution' of the (U.N. Security Council) against the DPRK," the official said in a statement carried by the KCNA, referring to the North by the initials of its official name.

Any arms aid would be a further sign of deepening ties between Moscow and Pyongyang as Russia's isolation over its war in Ukraine has grown.

North Korea was one of the only countries to recognize the independence of breakaway Ukrainian regions, and it has expressed support for Russia's proclaimed annexation of parts of Ukraine.