US President Barack Obama has backed Pentagon plans to close the detention facility at Guantanamo Bay.
President Obama said the site in Cuba undermines national security and US values.
The Obama administration has released its long-awaited plan to close the detention centre at Guantanamo Bay and transfer remaining detainees to a facility in the US, but the proposal ducks the question of where the facility would be located.
The plan delivered to Congress makes a financial argument for closing the controversial detention centre in Cuba. US officials say it calls for up to $475m in construction costs that would ultimately be offset by as much as $180m per year in operating cost savings.
The proposal is part of Barack Obama's last effort to make good on his unfulfilled 2008 campaign vow to close Guantanamo and persuade policymakers to allow the Defence Department to move nearly 60 detainees to the US.
But with few specifics, the proposal may only further antagonise policymakers who have repeatedly passed legislation banning any effort to move detainees to the US.
US officials say the plan considers, but does not name, 13 locations in the US, including seven existing prison facilities in Colorado, South Carolina and Kansas, as well as six other locations on military bases.
They say the plan does not recommend a preferred site and the cost estimates are meant to provide a starting point for a conversation with Congress.
The seven facilities reviewed by a Pentagon assessment team last year were the US Disciplinary Barracks and Midwest Joint Regional Corrections Facility at Leavenworth, Kansas; the Consolidated Naval Brig, Charleston, South Carolina; the Federal Correctional Complex, which includes the medium, maximum and supermax facilities in Florence, Colorado; and the Colorado State Penitentiary II in Canon City, Colorado, also known as the Centennial Correctional Facility.
According to the officials, the US facilities would cost between $265m and $305m to operate each year. The annual operating cost for Guantanamo is $445m.
More detailed spending figures, which are considered classified, will be provided to Congress, said the officials.
Late last year, other US officials said the assessments by the Pentagon team suggested that the Centennial Correctional Facility in Colorado is a more suitable site to send detainees whom officials believe should never be released.
Members of Congress have been demanding the Guantanamo plan for months, but those representing South Carolina, Kansas and Colorado have voiced opposition to housing the detainees in their states.
The administration is currently prohibited by law from moving Guantanamo Bay detainees to the United States. Mr Obama has long opposed that prohibition and the White House has not ruled out the possibility that the president may attempt to close the prison through executive action.
Advocates of closing Guantanamo say the prison has long been a recruiting tool for militant groups and that holding extremists suspected of violent acts indefinitely without charges or trial sparks anger and dismay among US allies.
Opponents say moving the detainees will not eliminate that problem.
There are currently 91 detainees at Guantanamo Bay, of whom 35 are expected to be transferred out by this summer.
The rest are either facing trial by military commission or have been determined to be too dangerous to release but are not facing charges. Some cannot be charged because of insufficient evidence and some may face future prosecution or have been designated for indefinite detention under the international laws of war.
Seven detainees are in the early stages of trial by military commission, including the five men accused of planning and aiding the September 11 terrorist attack, and three have been convicted and are serving sentences.
At its peak in 2003, Guantanamo held nearly 680 detainees, and there were about 245 when Mr Obama took office.