Karadzic was found guilty of one of the two counts of genocide in relation to the July-November 1995 mass murder of Muslim men and boys in the Bosnian town of Srebrenica, and the forced deportations of Muslim women, children and the elderly from the same town.
"This is one in a series of extremely harsh rulings by the ICTY against Serbs, that was passed amid acquittals for other participants of the civil war in former Yugoslavia — the Croatian general Ante Gotovina, the Kosovan Albanian Ramush Haradinaj and the Bosnian commander Naser Oric," the ministry said.
"In supporting the creation of the ICTY in 1993, Russia stated bluntly that the tribunal should not become a place for settling scores or a tool for revenge, but to become a true institution of justice that will lead to a triumph of justness and common sense…These expectations were not justified. Today, even the judges of the body declare the questionable methods of its work," the foreign ministry added.
The Republika Srpska is one of two administrative entities in Bosnia and Herzegovina, established in accordance with the Dayton Peace Accords in 1995 following the war.
Karadzic, 70, became the most high-profile defendant after the death of former Yugoslav President Slobodan Milosevic in 2006 before his trial concluded. His lawyer told RIA Novosti late on Thursday that the defense team planned to appeal the sentence within the next two years.