Former Liberian leader Charles Taylor has been transferred to the UN-backed war crimes tribunal in Sierra Leone.
Nigeria had ordered Mr Taylor's deportation to Liberia
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, hours after being caught trying to escape custody - ending his exile of nearly three years there.
The former president is wanted by the Sierra Leone tribunal for his alleged role in Liberia's brutal civil war.
He faces 17 charges of war crimes and crimes against humanity, and is accused of backing rebels notorious for mutilating civilians.
Mr Taylor was flown into the compound housing the court in the capital Freetown and taken into custody, where a cell was waiting for him.
The former leader had been in exile in Nigeria since 2003 after a deal ending Liberia's civil war.
He went missing on Monday from his southern villa after the country announced Liberia was free to detain him.
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
Mr Taylor was captured on Wednesday morning by security forces close to the Cameroon border, and then deported.
On arrival at the airport in Liberia's capital, he was led to a UN helicopter which took off for Sierra Leone.
Correspondents say the capture came as a relief to Nigeria, which had faced criticism for allowing him to escape, despite warnings he might flee.
The president denied it was negligent in its handling of the suspect.
Speaking in Washington, Olusegun 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.
For his part, Mr Bush welcomed the capture and said he appreciated Nigeria's work to apprehend him.
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 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.
Human rights activists have accused Mr Taylor of being at the centre of a West Africa-wide web of armed groups.
The court's chief prosecutor has said Mr Taylor is the third most wanted war crimes suspect in the world.
The special court was set up to try to bring to justice those responsible for crimes during the decade-long civil war which officially ended in 2002.
The tribunal was established with the agreement of Sierra Leone and operates under both Sierra Leone domestic law and international humanitarian law.
It is beyond the control of the UN Security Council and is managed by countries - led by Britain and the US - which are funding it.