The US army private suspected of giving classified data to WikiLeaks is being moved from a Marine jail south of Washington to a state-of-the-art facility at Fort Leavenworth in Kansas, where Pentagon officials said more extensive mental, emotional and physical health care will be available.
Jeh Johnson, the Pentagon's top lawyer, said the move does not suggest that Army Pfc. Bradley Manning's treatment at the Marine Corps base at Quantico, Virginia, was inappropriate.
The transfer, which Mr Johnson described as "imminent," comes in the aftermath of international criticism about Manning's treatment during his detention at the Marine Corps base at Quantico.
The conditions of Manning's detention have been the focus of repeated protests from human rights groups and politicians.
Mr Johnson, however, said: "The fact that we have made a decision to transfer this particular pre-trial confine ... should not be interpreted as a criticism of the place he was before."
Speaking to reporters during a hastily arranged briefing, Mr Johnson and Army Undersecretary Joseph Westphal acknowledged that the brig at Quantico was not designed to hold pre-trial detainees for more than a few months.
"This is the right decision, at the right time," said Mr Westphal. "We were looking at a situation where he would need an environment more conducive for a longer detention."
The new facility, they said, will be more open, have more space, and Manning will have a greater opportunity to eat and interact with other prisoners there.
They added that the move was in Manning's best interest because Leavenworth's Joint Regional Correctional Facility has a broader array of facilities, including trained mental, emotional and physical health staff.
Lieutenant Colonel Dawn Hilton, in charge of the medium-security detention facility at Leavenworth, said Manning will undergo a comprehensive evaluation upon his arrival to assess whether he is a risk to his own or others' safety.
The 150 inmates there, including eight who are awaiting trial, are allowed three hours of recreation per day, she said, and three meals a day in a dining area.
She said the facility, which opened in January, is designed for long-term detention of pre-trial inmates. Officials agreed that Manning's case, which involves hundreds of thousands of highly sensitive and classified documents, is very complex and could drag on for months, if not years.
Mr Johnson said that Manning, who has been at Quantico for more than eight months, can be moved now because his interview in the Washington region to determine his competency to stand trial has been completed. That interview lasted one day and was done on April 9.