State-run media KCNA said on Tuesday that North Korea called U.S. claims that it is giving Russia artillery ammunition for its war in Ukraine "groundless."

A statement made last week by White House national security spokesman John Kirby that artillery from North Korea was being shipped to Russia under the guise of supplies to the Middle East or Africa was disputed in a statement released on Tuesday.

"Recently, the U.S. is persistently spreading a groundless 'rumor of arms dealings' between the DPRK and Russia," North Korea's vice director of military foreign affairs of the Ministry of National Defence said in a statement, according to KCNA.

The criticism comes amid rising tensions on the Korean peninsula following a series of North Korean weapons tests last week, including an intercontinental ballistic missile, while the U.S. and South Korea conducted their largest-ever air force drill.

The "rumor" according to the statement, is part of the U.S.' "hostile attempt to tarnish the image of the DPRK in the international arena," using an acronym for North Korea's official name.

Kirby had stated that U.S. authorities did not know whether Russia had received the munitions but were monitoring the shipments.

In addition to the drones and other weapons that Russia has gotten from Iran, U.S. officials see the covert North Korean shipments as more proof that even Moscow's traditional artillery arsenals have shrunk over the course of eight months of fighting. According to the intelligence, North Korea is attempting to conceal the shipments by having the ammunition appear to be headed for Middle Eastern or North African nations.

The "significant" number of shells sent, according to Kirby, is enough to help Russia prolong the conflict, which began in February with Moscow's invasion of its former Soviet neighbor, but not enough to give Russia an advantage over Ukrainian forces, who are receiving support from the U.S. and NATO allies.

The specific condition of Russia's conventional munitions inventories is unknown, but Russia is "burning through tens of thousands of rounds a day," according to Adam Mount, the director of the Defense Posture Project at the Federation of American Scientists, who specializes in North Korea. "They're looking for ammunition anywhere they can get it."

North Korea's new warning to the U.S. came just a day after Pyongyang promised a "resolute and overwhelming" military reaction to last week's U.S.-South Korean war drills.

North Korea's military confirmed that its recent ballistic missile launches were in response to Washington and Seoul's so-called Vigilant Storm operation.