Clinton, who was serving US president at the time of the massacre, was selected to head the delegation by President Barack Obama.

As well as being joined by members of the US Congress, he will also be accompanied by Madeleine Albright. Albright, who was US Secretary of State between 1997 and 2001, is part of a bipartisan 10-member delegation including members of the Senate and House of Representatives.

The commemoration is scheduled for Saturday in Bosnia-Herzegovina.

Srebrenica has gone down in history as the worst massacre to have occurred on European soil since World War II.

Bosnian Serb troops, led by Gen. Ratko Mladic - who is currently on trial in the Hague - overran Srebrenica in July 1995, while it remained an enclave within Serb-held territory. Some 25,000 people remained in the town, seeking help from Dutch UN peacekeepers. the UN soldiers were outnumbered and the Serb forces immediately slaughtered some 2,000 men and boys, before pursuing and killing some 6,000 who fled into the forests.

As US President between 1993 and 2001, Clinton presided over the US response to conflict in the former Yugoslavia.

Peace talks to end war

After having waited for a European response to the conflict that never fully materialized, Clinton dispatched a high-level delegation to the Balkans, with the efforts leading to US sponsored peace talks at Dayton, Ohio. The Bosnian War officially ended on December 14, 1995.

In August 1995, as the chief US delegate to the United Nations, Albright notably displayed aerial photographs to the UN Security Council that showed mounds of freshly dug earth near to Srebrenica. The displaced soil had not been seen in previous pictures, and was consistent with mass burials having taken place.

Serbian Prime Minister Aleksandar Vucic has agreed to attend the commemoration event.

Vucic has said he would not attend the event if a resolution declaring Srebrenica to have been a genocide was passed by the UN Security Council. He said he had asked Russian President Vladimir Putin to intervene and, on Wednesday, Russia used its veto in the Council to block the British-proposed resolution.

rc/jr (AP, AFP, Reuters)