UNITED NATIONS — Serbia is pressing Russia to use its veto Tuesday against a British-drafted resolution marking the 20th anniversary of the 1995 massacre of some 8,000 Muslim men and boys at Srebrenica during the Bosnian war which condemns the killings as a crime of genocide.

Serbian state TV said Saturday that the country's pro-Russian President Tomislav Nikolic had sent a letter to Russian President Vladimir Putin "pleading" for a Russian "no" vote.

Supporters of the resolution had been hoping for unanimous approval by the UN Security Council, but that appears unlikely. Whether Russia uses its veto or abstains in the vote remains to be seen.

Russia, which has close cultural and religious ties to Serbia, circulated a rival draft resolution which doesn't mention either Srebrenica or genocide but no vote has been scheduled on it.

Last week, Russia's deputy UN ambassador Petr Iliichev called the British draft "divisive," saying the Russian draft is "more general, more reconciling."

Serbia's Foreign Minister Ivica Dacic wrote to the council on June 28 calling the British draft "unbalanced," ''unnecessary and detrimental," and harmful to the fragile reconciliation process in Bosnia.

Britain's UN Ambassador Matthew Rycroft stressed in a July 2 letter to Mladen Ivanic, the Serb member and current chair of Bosnia's tripartite presidency, that the International Criminal Tribunal for former Yugoslavia in 2004 and the International Court of Justice in 2007 both determined that the mass killings at Srebrenica were an act of genocide.

"That is not a political statement. It is a legal fact," Rycroft wrote. "What happened in Srebrenica was the worst single crime in Europe since the Second World War."

He stressed that any judgment of genocide deal with individuals — not an entire people — and he insisted that the resolution is not "anti-Serbian" as some have alleged.