I need Karadzic and Mladic in The Hague by July 11 in order to be able to attend the commemoration in Srebrenica, del Ponte told the press at the end of her visit to the Bosnian capital.
She underlined that the arrest of the two fugitives was the only way to remember with dignity the innocent victims whom Serb troops killed in Srebrenica, eastern Bosnia, in July 1995.
Del Ponte said that showing footage of the execution of Muslims captured in Srebrenica at the trial of ex-Yugoslav President Slobodan Milosevic was part of efforts to finally arrest the Bosnian Serb wartime leaders Karadzic and Mladic.
Del Ponte said the UN court's Prosecution had more such footage, which would likely be shown at one of the future trials.
Commenting on her talks in Sarajevo, the chief prosecutor said they were operational in nature. Behind closed doors, she held talks with the High Representative for Bosnia, Paddy Ashdown, and commanders of EU and NATO troops in Bosnia.
Answering a question from the press, del Ponte confirmed she was willing to reveal why NATO failed to arrest Karadzic and Mladic over the past 10 years. She said this could be expected unless the two ended up in The Hague by the end of the year.
But that is all history now, she said.