The 63-year-old Karadzic, who said he would be conducting his own defence, said he would like more time to study the charges against him before entering a plea.
Under court rules he is allowed 30 days to decide how to plead.
If he refuses to enter a plea then, a plea of "not guilty" is entered for him.
'Deal' with US
During Thursday's hearing, Karadzic alleged that he had made a deal with Richard Holbrooke, the US architect of the July 1996 Dayton peace accord, at the end of the 1992-95 Bosnian war that, involved Karadzic withdrawing from public life in return for immunity from prosecution.
|In Belgrade Karadzic disguised himself as an alternative healer [EPA]
It was agreed that he would lie low, Karadzic said, "in return the United States of America would fulfil their commitments".
But he did not say what these were.
Holbrooke denied on Thursday that he had entered into a deal with Karadzic.
"In June of 1996 I went to Belgrade and negotiated an agreement with Milosevic and two of Karadzic's henchmen that he would quit as president of the Serb portion of Bosnia, and as head of his political party, immediately and disappear from public life," Holbrooke said.
"He reluctantly signed that agreement without ever coming to the negotiations, but then in order to protect himself, he put out this false story."
In Washington, Sean McCormack, the state department spokesman, said the US had "from the first days of this administration been very consistent in urging the Serbian government to turn over Karadzic as well as others that are wanted to the International Criminal Tribunal in The Hague".
Karadzic also claimed irregularities in his capture, and contested the date of his arrest, but said that he had no complaints about his treatment at The Hague.
Following Thursday's proceedings, Alphons Orie, the presiding judge, said that the court would next meet on August 29.
Alan Fisher, Al Jazeera's correspondent in Belgrade, the Serbian capital, listened to the broadcast of the trial in a bar frequented by Karadzic supporters.
"People listened intently to what was said. One man who served as a Serbian soldier was in tears and said the process should be scrapped. They revere him as a leader of Bosnian Serbs and as a protector," Fisher said.
Speaking to Al Jazeera, Vedat Spahovic, a Bosnian journalist, said: "The beginning of the trial shows he is trying to spin his responsibility about what happened in the war.
"I would like to see justice. ... I am very glad to see Karadzic in the dock. I think he will have a fair trial. I don't feel any sympathy about Karadzic. Hopefully it won't last as long as the Milosevic trial."
Al Jazeera's Harry Smith, reporting from The Hague earlier, said: "This is the day everyone connected with the international tribunal has been waiting for.
|Karadzic's extradition has stirred strong nationalist sentiments in Serbia [AFP]
"It is the day many victims of the crimes in the former Yugoslavia have been waiting for ...
"The prosecutors are very eager to try and avoid that sort of disruption. Quite what they intend to do we don't know. But they say they have learnt a lot from the case of Milosevic."
Since his arrest in Belgrade last week, Karadzic has been shorn of the beard and the long hair that helped disguise him as an alternative healer in the years following the war.
He was flown to the Netherlands on Wednesday morning.
Question of defence
If Karadzic, in the manner of Slobodan Milosevic, the former Serbian president, does decide to defend himself, the move could protract the tribunal's proceedings.
For his part, Serge Brammertz, the chief prosecutor, has said he will conduct the trial efficiently, learning from the Milosevic case.
"Of course it will take some months before the prosecution and defence will be ready to start. It will be a complex trial but we are fully aware of the importance of being efficient," he said on Wednesday.
Brammertz called the arrest a "major achievement".
Karadzic's lawyer in Belgrade has said Karadzic believes he will be cleared of genocide.
Earlier this week relatives said Karadzic was in good spirits and preparing his defence.
Karadzic's delivery to The Hague was key to Serbia securing closer ties with the European Union and his arrest was seen as a pro-Western signal by the new government sworn in this month.