The government decided to lower the export duty it charges for crude oil from $271 to $267 per metric ton, Russia's state news agency RIA Novosti reports.
"The oil export duty has been established at a level similar to that introduced in Russia on Jan. 1," a spokesman for the Belarusian government said.
Russia in 2009 shipped roughly 25 million tons of crude oil to Belarus, though the bulk of those exports were transmitted to other countries in Eastern Europe.
Belarus received discounts on Russian oil imports in 2009. Moscow said it would consider concessions for Minsk in 2010, but not for its oil bound for European markets.
A brief trade conflict between Russia and Belarus concerned European oil consumers still reeling from a January 2009 row between Kiev and Moscow over gas prices and debt. Europe was left in the cold for weeks because of that dispute.