The three boys, aged between 13 and 15, were all captured by US forces in Afghanistan. Their detention has been heavily criticised by human rights groups.
“He's very close to making a recommendation,” Lieutenant Commander Barbara Burfeind, a Pentagon spokeswoman, told AFP.
In order for the boys to be freed, Miller must formally recommend they be released to Defence Secretary Donald Rumsfeld. None of the three have received legal representation.
Still, Miller has defended their detention arguing that they provided “very high value useful intelligence.”
"We send them to other countries so they can kick the [expletive] out of them”
Unidentified US official quoted by the Washington Post
In all, about 660 people are being held at the base. About 60 others have been sent back to Afghanistan and turned over to local authorities.
In December 2002 New York-based Human Rights Watch wrote a letter to President George Bush demanding immediate steps be taken "to clarify that the use of torture is not US policy".
The missive was inspired by a Washington Post story, in which interrogators from the Central Intelligence Agency (CIA) were said to have subjected Taliban and al-Qaida suspects to "stress and duress" techniques of dubious legality.
The newspaper said detainees at Guantanamo were generally treated better than those at other camps in other countries because journalists and Red Cross delegations were sometimes allowed to visit the Cuban penitentiary.
Still, many of those captured in Afghanistan were sometimes held in uncomfortable positions for hours and deprived of sleep at foreign bases.
Others were handed over to countries known to practice torture such as Morocco and Egypt.
“We don't kick the [expletive] out of them,” one unidentified US official told the Washington Post. “We send them to other countries so they can kick the [expletive] out of them.”