State Department spokesman Sean McCormack accused Belarusian officials of trying to use new transit fees on the westward oil shipments to maintain the personal profits of those around the authoritarian regime of President Alyaksandr Lukashenka.
"And so what the Belarusian government is now trying to do is pass along -- you know, they're still trying to keep their skim while they export this oil," McCormack said. "So it's just another example -- it's the rotten core of this regime, which they are using these resources for the personal profit of those around the leadership of the Lukashenka regime."
McCormack accused Moscow of seeking to use Russian energy resources as a "political lever" against neighboring states.
Belarus this week imposed the new transit fee on Russian crude after Russia late last year imposed a customs duty on exports to Belarus and, early this year, forced Belarus to pay twice as much as before for gas imports.
Both Russian and Belarusian officials have said they do not expect the row to have an impact on deliveries to third countries.
The main Moscow-Minsk railway line(Tass)
TO MERGE OR NOT TO MERGE: For over a decade, Moscow and Minsk have been working on a project to form a single state, the Russia-Belarus Union. However, every time the two countries seem on the verge of making progress, one or the other steps back, leaving the entire effort in doubt.