WASHINGTON -- The White House said Tuesday it will move its war court from Guantánamo Bay, Cuba, to President Barack Obama’s home state of Illinois, but officials could not say how soon or at what cost, and acknowledged they’ll need support from Congress to fully implement the transition.

Administration officials declined to estimate how many of the 210 detainees at Guantánamo would move to the Thomson Correctional Center, but White House Press Secretary Robert Gibbs said he “wouldn't get in the way of contradicting” an estimate by Sen. Richard Durbin, D-Ill, of about 100 detainees.

A letter to Illinois Gov. Pat Quinn and a presidential memorandum made official the federal government’s intention to acquire the largely empty maximum-security facility about 150 miles from Chicago.

A senior White House official said in a background briefing that the 146-acre prison was the intended site for the latest version of the military commissions trials, meant for war on terror captives accused of committing war crimes. The official also said the administration intended to transfer any so-called indefinite detainees to the facility, which would require congressional action.

Many Illinois officials and congressional Democrats support the idea, but Republicans cited concerns for Americans’ safety, and human rights advocates underscored opposition to indefinite detentions on or off U.S. soil. Others worried Obama is being rushed by the anti-war base.

The latest move comes after nearly a year of obstacles being thrown in the path of Obama’s plans to close the controversial prison camps in southeast Cuba. Sen. Lindsey Graham, R-S.C., a military lawyer, agrees with closing Guantánamo “if done correctly,” but suggested the latest development is more evidence that Obama’s team “has lost its bearings in an effort to close Guantánamo as quickly as possible.

“The Administration has sent a confusing message to our troops on the battlefield who no longer know when civilian law enforcement rules or the laws of war might apply,” Graham said.

But even advocates of Guantánamo's closure viewed the skeletal plan outlined Tuesday with skepticism. "If Thomson will be used to facilitate (detainees’) lawful prosecution, then this is truly a positive step," said Joanne Mariner, counterterrorism director at Human Rights Watch. "But if the administration plans to hold the detainees indefinitely in the Thomson prison without charging them, President Obama will simply have moved Guantánamo to Illinois."

“It will pose no danger to the community,” National Security Adviser James L. Jones said Tuesday, while Durbin vowed, “We will never forget 9/11.”

On paper, officials said, the facility first opened in 2001 would be the nation's most secure.

The letter to Quinn said acquiring Thomson would allow the federal government to carry out the president’s order to close the facility at Guantánamo, where terrorism detainees have been housed since 2002.

Reported abuses at Guantánamo during the Bush administration inflamed Islamic radicals and incurred disapproval from the international community. Obama ordered that the detention center at Guantánamo be emptied by Jan. 22, 2010 but has acknowledged the deadline can’t be met. Of detainees still at Guantánamo, five have been designated for federal trial, with another 25 under consideration. The Pentagon's Chief War Crimes Prosecutor, Navy Capt. John F. Murphy, has said his staff is building military commissions or war crimes court cases for up to 55 of the 210 detainees now at Guantánamo.