Judges have rejected an appeal of extradition. Mladic was allowed out of his jail cell for a short time on Tuesday to visit his daughter's grave.
She died in 1994. At the time, the media reported she committed suicide over her father's role in the Bosnia war.
Mladic claims she was killed by his wartime enemies.
Mladic is charged with the 1995 massacre of some 8,000 Muslims in Bosnia.
He was arrested Thursday in a village north of Belgrade after 16 years on the run, looking worn and disheveled. The defense argued in an appeal it mailed to the courthouse that the 69-year-old is not mentally and physically fit to stand trial.
The Associated Press contributed to this story.