Western nations and Russia are dueling over whether the U.N. Security Council should call the Srebrenica massacre during the Bosnian war a genocide in a resolution commemorating the 20th anniversary of Europe's worst mass killing since World War II.

Britain has circulated a draft U.N. Security Council resolution, which was seen Tuesday by The Associated Press, that "condemns in the strongest terms the genocide in Srebrenica." It recalls that the Yugoslav war crimes tribunal in 2004 and the International Court of Justice in 2007 both determined that the killing of more than 8,000 Bosnian Muslims in July 1995 were acts of genocide.

Bosnian Serb leaders have been charged with ordering the mass killings of the Muslim men and boys taken from a U.N.-protected enclave in the eastern Bosnian town.

But calling what happened in Srebrenica a genocide has touched off a wave of protests in Serbia.

Serbian Prime Minister Aleksandar Vucic, a former extreme nationalist who now declares himself a pro-European Union reformer, has said he is ready to attend memorial ceremonies marking the Srebrenica anniversary — but he refused to call it a genocide. Instead, he said a "big horrific crime" took place in Srebrenica.

Russia, which has close religious ties to Serbia, has circulated a rival draft resolution, also seen Tuesday by the AP, which doesn't mention either Srebrenica or genocide. Instead, it "condemns in the strongest terms the most serious crimes of concern to the international community as a whole committed during the conflicts in the former Yugoslavia against persons of various ethnic and religious backgrounds."

The U.N. General Assembly will commemorate the Srebrenica anniversary on Wednesday, but whether the Security Council will adopt a resolution remains to be seen since Russia as a permanent member has veto power.

The council is scheduled to discuss the commemoration on July 7 and Serbia has been pressing for a Russian veto of the Western-backed resolution.

Britain's U.N. Ambassador Matthew Rycroft said "the 20th anniversary of the Srebrenica genocide is a moment to pause and reflect on the lessons learned of the darkest moments in U.N. history and commit to making 'Never Again' a reality."

He said the British draft will commemorate not only the Srebrenica victims but all those who suffered on all sides of the war and will encourage further steps toward reconciliation in deeply divided Bosnia and affirm the council's determination to prevent future genocides, crimes against humanity and war crimes.

But Russia's deputy U.N. ambassador Petr Iliichev on Tuesday called the British draft "divisive," saying it focuses on "only one part of the conflict."

The Russian draft, he said, is "more general, more reconciling."