Bosnian Serb wartime leader Radovan Karadzic defiantly demanded more time to prepare his defence Tuesday as he made his first court appearance since the start of his genocide trial.

Wearing a black suit, pink shirt and red tie, Karadzic entered the accused dock of the International Criminal Tribunal for the former Yugoslavia for a hearing to determine how to proceed in the face of his boycott.

Karadzic faces 11 war crimes and genocide charges over the 1992-95 Bosnia war, including for the massacre of more than 7,000 Muslim men and boys at Srebrenica and the 44-month siege of Sarajevo in which 10,000 people were killed.

"I don't want to boycott these proceedings, but I cannot take part in something that has been bad from the start or where my fundamental rights have been violated," Karadzic told judges, demanding more time to prepare.

"The situation is such that I would really be a criminal if I were to accept these conditions -- to enter into a trial and proceedings for which I am not prepared."

Karadzic is conducting his own defence.

Presiding judge O-Gon Kwon adjourned the trial, cancelling a hearing scheduled for Wednesday, to consider submissions made by Karadic and the prosecution on the future of the trial. He said a written decision will be released later this week."

Karadzic, who denies all the charges against him, could be jailed for life if convicted.

He is charged with 11 counts of genocide, war crimes and crimes against humanity for his role in the 1992-95 Bosnian war that claimed some 100,000 lives and caused 2.2 million people to flee their homes.

Arrested on a Belgrade bus last July after 13 years on the run, he has refused to leave his jail cell since the trial started on October 26, saying he needs more time to review 1.3 million pages of prosecution evidence and the statements of hundreds of witnesses.

"I have given up my walks in the fresh air and sports," working day and night to prepare for the case, said Karadzic.

But the judge pointed out that the court had found on more than one occasion that he had had enough time to prepare.

"It is the trial chamber, not an accused person which determines readiness for trial," O-Gon said. "It is in your best interest to attend and participate fully in the trial so that justice can be done."

Prosecutor Hildegard Uertz-Retzlaff urged the court to allow the proceedings to continue, accusing Karadzic of "obstructive behaviour."

"Mr Karadzic cannot be permitted to manipulate the proceedings through his decision not to attend," she said, warning that "if necessary, force can be used to secure his presence in the courtroom."

Other options include continuing the trial in Karadzic's absence, or imposing a defence lawyer -- a step that could delay the proceedings and which he has vowed to fight.

"There is no single lawyer that wouldn't need more time than this defence team that is under my leadership," Karadzic told the judges.

"What my defence needs most is not a new lawyer, what it needs most is more time."

Co-prosecutor Alan Tieger has branded Karadzic "the "supreme commander" of an ethnic cleansing campaign of Croats and Muslims during Bosnia's war.

Karadzic is alleged to have worked with Yugoslav strongman Slobodan Milosevic in pursuit of a "Greater Serbia" which was to include 60 percent of the territory of Bosnia.

Milosevic died midway through his own genocide trial in March 2006, while Karadzic's former military general, Ratko Mladic, is still on the run.