The EU sanctions have started last week on Thursday, accusing the airline to fly illegal migrants to the European countries as part of Russia's plan to destabilize EU territory.
"Due to the imposition of restrictions, the airline has been forced to reduce its fleet," Belavia said in a statement, adding it currently had 15 aircraft.
The carrier did not specify which of its previous 14 Boeing and 15 Embraer aircraft were no longer in service.
Belavia has been banned from using Europe's airspace in its flights after the Belarussian government grounded a Ryanair jet in Belarus and arrested an anti-government activist.
