Since March, Russia has reportedly supplied North Korea with over a million barrels of oil, according to an analysis conducted by the UK-based research group Open Source Centre in collaboration with the BBC. Satellite imagery provided by the BBC revealed that North Korean oil tankers made 43 visits to an oil terminal in Russia’s Far East over the past eight months, with some tankers arriving empty and leaving nearly full.

The shipments, which are part of an arrangement for weapons and troops from North Korea sent to assist Russia in its ongoing war in Ukraine, violate UN sanctions. These sanctions prohibit the sale of oil to North Korea, except in small quantities, as part of efforts to restrict its economy and curb its nuclear weapons development.

North Korea is the only country globally not permitted to purchase oil on the open market. Under UN sanctions, the country is allowed to receive a maximum of 500,000 barrels of refined oil per year, a quantity far less than what it needs. The shipments from Russia have sparked concerns from experts and UK Foreign Secretary David Lammy, who emphasized that the violations of sanctions are directly tied to North Korea’s support for Russia’s military actions.