Ukraine has taken aim at South Korea over oil products sent to Russia at a time when Ukrainian attacks had disrupted Moscow’s refining operations, arguing that the supplies helped ease the effects of the damage.
The Guardian reported that 176,000 tonnes of oil products were shipped from South Korea to Russia in July and August, citing port records and ship-tracking information. The data did not identify the companies or individuals that owned or sold the fuel.
Vladyslav Vlasiuk, President Volodymyr Zelensky's adviser on sanctions, said the deliveries raised concerns because they arrived as Russia was dealing with reduced fuel production following attacks on its refineries.
"These deliveries began precisely when Ukrainian strikes on Russian refineries reduced processing volumes and created a fuel shortage in the Russian Federation," Vlasiuk said.
He said the imports had helped Moscow cover part of the gap created by the decline in domestic refining.
"In other words, imports from South Korea effectively helped Russia offset the consequences of losing its own refining capacity.
"This stands in sharp contrast to what South Korea had been doing in terms of sanctions policy after the start of the full-scale invasion."
Vlasiuk added that diesel made up most of the oil products shipped to Russia from South Korea during the two months.
The Guardian's review of shipping information found that the cargoes represented 31 percent of Russia's fuel imports by sea in July and August. Seven tankers were involved in transporting the products, three of which were subject to Western sanctions, according to the report.
The latest dispute comes against the backdrop of a separate diplomatic disagreement between Kyiv and Seoul over two North Korean soldiers captured while fighting with Russian forces.
Zelensky disclosed in a speech at the United Nations last month that the two North Korean prisoners of war had been sent to South Korea.
The disclosure angered Seoul, which has summoned Ukraine's ambassador and warned of unspecified "further measures". President Lee Jae Myung has also demanded an official apology, with South Korean authorities concerned that the disclosure could expose the families of the captured soldiers to possible danger.
Zelensky has denied violating an agreement requiring confidentiality over the prisoners' transfer. Ukraine's Foreign Minister Andriy Sybiga has instead described the disagreement as a "diplomatic misunderstanding".
The dispute over the oil shipments now places another issue between the two countries under scrutiny, with Kyiv questioning whether the deliveries fit with Seoul's wider restrictions on Russia.
South Korea joined a group of countries that strengthened export controls on Russia and Belarus after Moscow launched its full-scale invasion of Ukraine in 2022.
Seoul has also imposed restrictions involving major Russian banks and the central bank, while limiting other financial dealings and trade in a range of goods. Some of the restricted products are items that could be used for defence purposes.
For Ukraine, the timing of the reported oil deliveries is central to its criticism. Kyiv says the shipments reached Russia as strikes on its refineries had cut processing capacity and contributed to a shortage of fuel, allowing imported supplies to help fill the resulting gap.