Karadzic is accused of 11 counts of genocide, war crimes and crimes against humanity for his role in Bosnia's 1992-5 war, which claimed an estimated 100,000 lives.
Mass murder charge
The charges allege he orchestrated crimes including the 44-month siege of Sarajevo that left 10,000 people dead and the July 1995 massacre of around 8,000 Muslim men and boys at Srebrenica.
Karadzic denies all charges against him and has chosen to make his own legal defence. He faces a maximum sentence of life imprisonment if convicted.
In his six-page letter to the court, the former leader argued he should have been given "at least two years" to prepare for his trial.
"No lawyer in this world could prepare defence within this period of time.
"This trial, being the most gigantic, should have been given at least the average time for preparation, which is almost two years," he said.
But Nerma Jelacic, an ICTY spokesperson, said: "At the moment there is no indication that the procedure will not go ahead as scheduled. The control of court proceedings is entirely in the hands of the tribunal's judges."
Rodney Dixon, a former legal adviser to the ICTY and a specialist in international criminal law, told Al Jazeera on Thursday that the prosecution had indeed had much longer to prepare its case against Karadzic, who was arrested in July 2008.
"It's a big case. He might have a point that he needs more time ... it's a lot of material to go through in a year, when the prosecution had considerably longer," Dixon said.
"But that doesn't mean the trial couldn't start ... parts of it could begin and he could be given more time as and when he needs it."
Dixon also said that court has the power to appoint a lawyer to represent Karadzic's interests if he refuses to attend. "It'll be for the court to determine that next week ... but they did so in the Milosevic case".
And while acknowledging that families of victims feel that the delay for justice has already been too long, the former ICTY adviser noted that "these are very serious allegations. They will take a long time to investigate".
Karadzic was arrested on a Belgrade bus in July 2008, posing as a bearded alternative healer, after 13 years on the run.