Russia resumed oil exports to North Korea in December, United Nations (U.N.) data shows, the first such shipments reported since 2020 as the two countries deepen ties and the United States flags the risk of arms supplies to Moscow.

North Korea has been seeking closer relations with the Kremlin and backed Moscow after it invaded Ukraine last year, blaming what it called the "hegemonic policy" of the United States and the West.

Russia had exported 67,300 bbl of refined petroleum to North Korea by April, the first deliveries reported to the U.N. since Moscow said it shipped 255 bbl of refined oil to the North in August 2020.

Under U.N. sanctions against Pyongyang's nuclear and missile programs, countries are required to report monthly sales of refined petroleum to the Security Council North Korea sanctions committee.

The oil sales began shortly after train travel between Russia and North Korea resumed in November for the first time since 2020, raising expectations of a resumption of trade.

The United States is concerned North Korea is planning to deliver more weapons to Russia, a State Department spokesperson said on June 12 after North Korean leader Kim Jong Un vowed to bolster strategic cooperation with Moscow.

Despite Pyongyang's denials that it had sold weapons to Russia, the United States confirmed North Korea completed an arms delivery, including infantry rockets and missiles, to the Kremlin-backed Wagner mercenary group in November, the spokesperson said.