The Pentagon on Wednesday urged Congress to avoid an early closing of the U.S. military prison in Cuba, despite widespread recognition that the infamous jail has eroded U.S. standing in the world.

Defense officials told the U.S. House of Representatives that it could take about three years to try 60 to 80 Guantanamo Bay inmates identified as terror suspects who could be successfully prosecuted on war crimes charges before military tribunals.

Others from among a current prison population of 385 inmates would also require years to gain release or be transferred into the custody of their home countries.

Although President George W. Bush and Defense Secretary Robert Gates have both expressed a desire to close the prison, officials appearing before a House Appropriations subcommittee suggested closure would be a long-term project with a range of nettlesome legal and security issues to be resolved.

"Neither the president nor the secretary has said we're going to close it tomorrow," said Joseph Benkert, principal deputy assistant defense secretary for global security affairs.

"There are no readily available facilities to take these guys," he added, stressing that the administration has no timeline or proposal for shutting the jail.

The prison at the U.S. naval station at Guantanamo, which has housed about 775 terrorism suspects since it opened in early 2002, has been condemned worldwide as an affront to human rights because most inmates are held without charge.