SERBIA'S prime minister, an ultra-nationalist during the Yugoslav wars of the 1990s, has said he is willing to attend the 20th anniversary commemoration of the Srebrenica massacre and bow his head to the more than 8,000 victims.

Aleksandar Vucic's attendance at the July 11 ceremony in eastern Bosnia will mark a highly symbolic moment in the Balkan region's recovery and reconciliation after wars that killed some 135,000 people during the breakup of Yugoslavia.

Former Serbian President Boris Tadic was present at the 15th anniversary ceremony in 2010, but Vucic is far more closely associated with Serbia's nationalist past and the Greater Serbia ideology that fuelled much of the bloodshed.

In Srebrenica, more than 8,000 Muslim men and boys were killed when the designated United Nations "safe area" fell to Bosnian Serb forces, who were backed by money and men from Serbia during the war.

It was widely regarded as the worst massacre on European soil since World War Two, and a U.N. court has ruled it constituted genocide. Victims were dumped in pits, then unearthed with diggers and reburied in scattered smaller graves in a bid to hide the crime. Remains are still being exhumed.

"If (Muslim) Bosniaks want it, if it is not too hard for them ... I am ready to pay my respects to the Muslim and Bosniak victims of Srebrenica," Vucic told a news conference.

"As prime minister, I am ready to bow my head to show the stand we take towards the innocent victims of Srebrenica," he said. "I will go there regardless of the risks."

Serbia is under pressure from the West to improve relations with its ex-Yugoslav neighbours if it is to make progress on the road to membership of the European Union, with the bloc weighing whether to begin accession talks in earnest this year or next.

During the wars, Vucic was a senior member of the ultra-nationalist Serbian Radical Party, and once threatened in parliament that 100 Muslims would be killed for every Serb victim in Bosnia.

He broke away from the party in 2008, embracing Serbia's EU bid and rebranding himself as a pro-Western reformer.