Belarus has increased by around a third the transit fees for Russian oil heading through pipelines to Europe. The Energy Ministry in Minsk said the price hikes - the first in 11 years - are justified as they will help offset the cost of Moscow's doubling of energy prices it charges Belarus.
Russia did not immediately comment but recently said Belarus could not raise transit prices without its agreement.
Western European markets receive around 80 million tons of Russian oil through Belarusian pipelines every year via Poland, Hungary, Ukraine, Slovakia, and the Czech Republic.
Belarus' President Alexander Lukashenko has recently fallen out with Moscow which accused his government of making money by refining cheap Russian oil and selling higher-value products on to Europe. Minsk denied that.
That dispute disrupted European oil shipments for several days. It also led to tit-for-tat trade restrictions between the two countries.