Former US President Bill Clinton is to formally open a cemetery and memorial to the thousands of victims of the Srebrenica massacre in Bosnia in 1995.
More than 800 victims have already been buried at the cemetery
Mr Clinton was invited by the families of victims of the massacre because of his personal efforts to end the 1992-95 war, said Bosnia High Representative Paddy Ashdown.
More than 800 victims exhumed from mass graves have already been buried at the new cemetery in Srebrenica, but its official opening will be held in September.
The massacre's eighth anniversary was marked last month, in a ceremony attended for the first time by the prime minister of the Bosnian Serb entity.
The massacre was the worst in Europe since World War II.
Some 8,000 Muslims, mainly men and boys, were slaughtered by Bosnian Serb soldiers who in 1995 overran the town in eastern Bosnia, which was supposed to have been under United Nations protection.
Clinton ordered air strikes on the Bosnian Serbs
The massacre is one of the main charges brought against Bosnian Serb wartime leaders Radovan Karadzic and Ratko Mladic, who are still at large.
It prompted the international community - led by Mr Clinton - to seek to end the conflict by ordering air strikes against the Bosnian Serbs.
"It is fitting that the man who did so much to end the war should open the memorial that will ensure that the victims of this massacre - indeed all the victims of this terrible war - are not forgotten," Mr Ashdown said.
Construction of the $5.7m memorial began in October last year.
But Mr Ashdown said money was still needed to complete it.
The Bosnian Serb government has been told to pay more than $1m towards the project.