Russia has been shipping refined petroleum to North Korea in volumes that may violate the U.N. Security Council's restrictions, U.S. National Security Council spokesperson John Kirby said on May 2, according to Reuters.
The reports came after the Financial Times wrote that Moscow was defying U.N. sanctions by supplying North Korea with oil, likely in exchange for weapons. Pyongyang is subject to a strict cap on oil transfers, imposed by the U.N. Security Council in 2017 after a series of nuclear weapons tests.
Moscow supplied over 165,000 barrels of refined petroleum to North Korea in March alone, Kirby said.
North Korea is limited to importing 500,000 barrels of petroleum products per year under U.N. sanctions.
Moscow vetoed in late March the annual renewal of the panel of experts monitoring U.N. sanctions against Pyongyang over its nuclear and ballistic missile programs, presumably to hide its own violations of Security Council resolutions, Reuters wrote.
The move was condemned by several other U.N. members, who accused Russia of shielding its purchases of North Korean arms for its war effort against Ukraine.
Washington would continue to impose sanctions "against those working to facilitate arms and refined petroleum transfers" between Moscow and the Pyongyang, Kirby said.
Pyongyang has been shaping up as Russia's leading weapons supplier, reportedly providing Moscow with extensive military packages, including ballistic missiles and over 3 million artillery shells.
There have also been concerns about what Russia may be providing North Korea in return for the shipments of military hardware and ammunition. U.S. Secretary of State Antony Blinken has warned that Russia has been assisting North Korea in upgrading its military capabilities, potentially including ballistic missiles and nuclear technology.
There has been at least 10 cases of Russia using North Korean missiles to strike Ukraine, said Jung Pak, the U.S. Senior Official for North Korea, in late March.