Reluctance by other countries to take custody of terrorism suspects held at Guantanamo Bay is delaying Washington's shutting of the widely criticized prison, U.S. President George W. Bush said on Thursday.

"I did say it should be a goal of the nation to shut down Guantanamo," Bush told reporters. "I also made it clear that part of the delay was the reluctance of some nations to take back some of the people being held there."

Washington has faced fierce criticism worldwide for the detention without charge -- often for years -- of suspected al Qaeda and Taliban members at the prison on a U.S. naval base in Cuba.

While members of the Bush administration have repeatedly said they would like to close the facility, they also say it is needed in the U.S.-declared war on terrorism.

The United States holds 355 detainees at the Guantanamo Bay detention center, set up to handle prisoners captured by the United States after the Sept. 11 attacks in 2001.

Of the total detainees, the Pentagon says 80 are eligible for release or transfer to another country. Reviews over the next year could put another 75 to 80 detainees on track for transfer, according to Sandy Hodgkinson, deputy assistant secretary of defense for detainee affairs.

That would whittle the detainee population at Guantanamo down to about 200 if the United States is able to strike agreements with other nations to accept custody of the detainees and ensure they remain monitored.

Already, 25 of the 80 detainees currently eligible for transfer cannot be returned to their home nations because of human rights concerns, Hodgkinson said.

U.S. officials did not specify which countries were reluctant to accept prisoners but in the past the United States has transferred detainees to countries including Britain, Australia, Saudi Arabia, Kuwait, Iran, Pakistan and others.

Britain asked the United States on Tuesday to release five detainees from Guantanamo who were legal residents of Britain before their detention, although not British nationals.

Pentagon spokesman Bryan Whitman said the U.S. government was still reviewing the request and no decision had been made.

'ENEMY COMBATANTS'

The Pentagon also said the top 14 al Qaeda suspects at Guantanamo, including the accused mastermind of the Sept. 11 attacks, have been formally classified as "enemy combatants," a label that allows the U.S. government to keep holding them.

The classification of the 14 was announced on Thursday, although Deputy Defense Secretary Gordon England had made each detainee's status determination earlier.

The decisions follow hearings held at the prison from March through June to determine the status of the men, transferred last year to Guantanamo from secret CIA prisons.

The hearings, known as Combatant Status Review Tribunals, are administrative and not meant to determine guilt. But the government presents evidence against each detainee in those hearings and gives the detainee an opportunity to respond.

Charges have not been filed against any of the 14, including Khalid Sheikh Mohammed, who during his status hearing took responsibility for 31 attacks or planned attacks, including the Sept. 11 attacks.