On an official visit to Paris, Holder stressed what he called unprecedented intelligence-sharing ties between France and the United States against a united enemy, al Qaeda, that he said still held the two countries and its allies in its sights.

The recent killing of al Qaeda leader Osama bin Laden was unlikely to affect the timing of the closure of the Guantanamo facility, Holder said.

US President Barack Obama pledged to shut down the Guantanamo Bay facility in the first year of his presidency and transfer its inmates to prisons in the US.

Obama has said the centre, set up by his predecessor George W. Bush, has helped drive recruitment for anti-American groups and that allegations of mistreatment of prisoners have hurt America's reputation.

Holder said it would take time for intelligence and law enforcement agencies to go through the trove of data collected from bin Laden's compound, adding the information would be shared with allies as soon as possible.