"We have received a notification from BNK that part of oil product supplies through Klaipedos Nafta's terminal has been suspended and we are currently waiting for more detailed information from the customer," Darius Silenskis, oil business director at Klaipedos Nafta, told BNS.

"We are working with the customer on the basis of a take or pay contract. Therefore, we believe that the annual contractual obligations will be fulfilled," he added.

Under Klaipedos Nafta's three year-contract with BNK, which expires in late October 2019, oil products come to Klaipeda from Belarus' key refineries in Mozyr and Naftan. Information as to the volume of Belarusian oil products handled via Klaipeda is not publicly available.

BNK said it has suspended gasoline and diesel fuel exports to the Baltic countries, Poland and Ukraine. BNK Deputy CEO Sergei Grib said the company was forced to cut oil-refining volumes after receiving low-quality Russian oil.