Karadzic due in war crimes court
The former Bosnian Serb leader, Radovan Karadzic, is due to be formally charged by the UN war crimes tribunal, reported BBC.
Mr Karadzic was indicted on 11 counts of war crimes in connection with the 1990s Bosnian conflict, but the exact charges will only be revealed in court.
He will be asked to enter a plea, but he is under no obligation to do so.
Mr Karadzic was arrested in Belgrade last week after 13 years on the run, and extradited to the Netherlands where he is being held at a detention centre.
Mr Karadzic will appear before the International Criminal Tribunal for the former Yugoslavia (ICTY) at 1600 local time (1400 GMT) and then will have 30 days to enter a plea.
He was said by his lawyers to have been in a "relaxed and confident" mood on the eve of his extradition to the Netherlands in the early hours of Wednesday.
Speaking at a news conference on Wednesday, the tribunal's chief prosecutor, Serge Brammertz, said Mr Karadzic's arrest was "immensely important", adding that the victims of the war had "waited too long for this day".
However, both prosecution and defence teams said they would need months to prepare for the trial.
In addition, Mr Karadzic has said that he does not recognise the court and plans to conduct his own defence.
As such, this first court appearance likely to be just the opening skirmish in a long legal battle, says the BBC's Dominic Hughes in The Hague.
Mr Karadzic left Belgrade on Wednesday hours after clashes at a rally attended by at least 10,000 supporters to protest about his arrest.
He then took a special flight to Rotterdam airport in the Netherlands, from where he was transferred to the UN's detention unit.
The 63-year-old had reportedly attempted to challenge the legality of his transfer, but a senior member of his legal team has now told the BBC that no appeal was ever lodged.
Goran Petronijevic, who joined the Karadzic legal team on Tuesday, admitted that reports of an appeal being sent by post to the authoritities in Serbia had been a ruse designed to delay Mr Karadzic's extradition in order to allow time for his family to visit him in jail.
However, a travel ban on his family was lifted on Wednesday, to allow them to visit him in The Hague.
Their documents had been confiscated in January under suspicion that they were helping Mr Karadzic in hiding.
Mr Karadzic was arrested on 21 July in Belgrade. He had changed his appearance, having grown a long beard, and was working as an alternative therapist.
He is reported to have shaved his beard and had a haircut while he has been in custody.
Mr Karadzic led the formation of a separate Bosnian Serb assembly in 1991 - one of the sparks that ignited the 1992-1995 Bosnian war.
He has been indicted for crimes against humanity and genocide over the massacre of up to 8,000 mainly Muslim Bosniaks at Srebrenica in 1995.
He has also been charged over the shelling of Sarajevo, and the use of 284 UN peacekeepers as human shields in May and June 1995.
On Tuesday, EU ambassadors meeting in Brussels decided to defer a decision on unfreezing trade benefits for Serbia until Mr Karadzic was transferred to The Hague.
The EU is also demanding the arrest of Mr Karadzic's wartime military commander General Ratko Mladic, who remains at large.