Former Liberian leader Charles Taylor may not go on trial for many months, the case's chief prosecutor says.
Charles Taylor passed briefly through Liberia on his way to the court
Mr Taylor is being held by the war crimes tribunal in Sierra Leone, after he was captured trying to flee Nigeria on Wednesday.
He faces charges of crimes against humanity, including responsibility for murder, rape and mutilation.
US President George Bush welcomed his arrest, but suggested his trial move to The Hague for security reasons.
Mr Bush, meeting Nigerian President Olusegun Obasanjo at the White House, said he believed a UN Security Council resolution authorising the move could be passed "relatively quickly".
Desmond de Silva, chief prosecutor of the Special Court for Sierra Leone, set up to prosecute those responsible for the country's brutal civil war, said Mr Taylor would make his first court appearance by the end of this week, but that the trial was "many months away".
"Today is a momentous occasion, an important day for international justice, the international community, and above all the people of Sierra Leone," he said on Wednesday.
Sacks of cash
British Foreign Secretary Jack Straw said the crimes of which Mr Taylor is accused "are some of the gravest imaginable".
1997: Elected Liberian president after leading rebellion
1991-2002: Alleged role in Sierra Leone's civil war
June 2003: Arrest warrant issued by Sierra Leone tribunal
August 2003: Begins exile in Nigeria after civil war at home
March 2006: Detained by Nigeria while fleeing
He faces 11 charges of war crimes and crimes against humanity, over his alleged role fomenting war in Sierra Leone. Prosecutors have discarded six charges for a more "focused" trial.
UN Secretary-General Kofi Annan said his transfer to the tribunal "sends a powerful message to the region that impunity will not be allowed to stand and would-be warlords will pay a price".
Mr Taylor was flown to the court after being taken into UN custody in the Liberian capital, Monrovia.
He was repatriated from Nigeria on Wednesday, where he had been in exile for nearly three years, under a deal ending Liberia's civil war.
After Liberia's new President Ellen Johnson Sirleaf said she wanted him to face trial, and Mr Obasanjo agreed to help, Mr Taylor fled.
He was captured on Wednesday morning by security forces close to the Cameroon border, trying to flee in a jeep, with sacks stuffed full of dollars and euros.
Mr Obasanjo said he felt "vindicated" by the capture.
Those who had suggested Nigeria may have been complicit in Mr Taylor's initial escape were wrong and owed him an apology, he added.
The legal advisor to his National Patriotic Party told the BBC they would help Mr Taylor mount his legal defence in the Sierra Leone court.
Over the past week, the Liberian authorities have arrested several people alleged to back Mr Taylor amid fears that his detention could lead to unrest in Liberia.
Diamonds and weapons
Mr Taylor started Liberia's civil war as a warlord in 1989, before being elected president in 1997.
He is accused of selling diamonds and buying weapons for Sierra Leone's Revolutionary United Front rebels, who were notorious for hacking off the hands and legs, ears and lips of civilians during their decade-long war.
Tens of thousands of people died in the interlinked conflicts in Sierra Leone and Liberia.
Instability also spread into neighbouring parts of Ivory Coast and Guinea.