Two Russian ships owned by U.S.-sanctioned companies were seen transporting what are believed to be North Korean munitions in recent months, a British security think tank reported Monday, citing dozens of high-resolution satellite images.The Royal United Services Institute (RUSI) warned that the alleged emerging supply route could have “profound consequences for the war in Ukraine and international security dynamics in East Asia.”Pyongyang and Moscow have not responded to the latest claims.

The two countries have previously denied making weapons deals against the backdrop of their warming relations and Russia’s war on Ukraine, which has left Moscow’s stockpiles depleted after 20 months of fighting.RUSI identified the Russian-flagged Angara and Maria as making at least four trips to and from the secluded Russian port of Dunai and North Korea’s Najin between August and October 2023.The United States sanctioned the companies that own the vessels — M Leasing and Marine Trans Shipping — soon after Russia invaded Ukraine in 2022 for transporting weapons on behalf of the Kremlin.The Angara and Maria’s cargoes reportedly made their way to a rapidly expanding munitions storage facility in the small town of Tikhoretsk in southern Russia’s Krasnodar region, which is located near annexed Crimea and 200 kilometers from the border with Ukraine. “From here, North Korean weapons and munitions could be shipped to logistics depots on the border of Ukraine for distribution to frontline units,” RUSI said.RUSI shared the images days after the White House accused North Korea of delivering more than 1,000 containers of military equipment and munitions to Russia in exchange for advanced Russian weapons technologies.A “dramatic and unprecedented” increase in rail traffic along the North Korea-Russia border was reported last week by Beyond Parallel, a website run by the Washington-based Center for Strategic and International Studies think tank.North Korean leader Kim Jong Un visited Russia last month amid Western fears the isolated country could supply Moscow with weapons for its assault in Ukraine.Russia and North Korea, historic allies, are both under rafts of global sanctions — Moscow for its Ukraine offensive, and Pyongyang for its nuclear weapon tests.Moscow is believed to be interested in buying North Korean ammunition to continue fighting in Ukraine, while Pyongyang wants Russia's help to develop its internationally condemned missile program.AFP contributed reporting to this article.