President George W Bush has said that shutting down the US prison camp at Guantanamo Bay was not easy, but US officials were working to make it happen.
Mr Bush said the task of closing the camp was complicated because inmates' home nations did not necessarily want them back. He siad; "A lot of people don't want killers in their midst, and a lot of these people are killers."
He also noted delays in setting up trials for those who were being held.
The president, in a White House news conference before heading to his summer holiday, said the sooner that tribunals could start for inmates of the camp the better it is.
Meanwhile, 14 terrorist suspects, including the alleged mastermind of the 11 September attacks, have been officially designated 'enemy combatants' by the US after reviews at Guantanamo Bay.
All 14 detainees were moved to Guantanamo last year from secret CIA prisons overseas, and brought before military tribunals that reviewed their cases.
US Deputy Defense Secretary Gordon England approved the tribunal determination that the 14 detainees meet the criteria for designation as enemy combatants.
He said military prosecutors will decide whether they can bring charges against them for trial by a special military commission.
The 14 include Khalid Sheikh Mohammed, a Kuwaiti-born Pakistani, who is alleged to have directed the 11 September, 2001 attacks on New York and Washington with hijacked airliners.
At a hearing before a tribunal in March, Khalid Sheikh Mohammed confessed to plotting the attacks and claimed he was behind a slew of others.
