WASHINGTON (CNN) - The U.S. Senate passed a measure Wednesday that would prevent detainees at the U.S. military prison at Guantanamo Bay, Cuba, from being transferred to the United States for now.
The measure passed with overwhelming bipartisan support in a 90-6 vote. A similar amendment has already passed the House. It was attached to a supplemental war funding bill.
Following in the steps of House Democrats, Senate Democrats rejected on Tuesday the administration's request for $80 million to close the Guantanamo facility. They instead asked that President Barack Obama first submit a plan spelling out what the administration will do with the prisoners when it closes the prison.
The moves by the Democratic-controlled Congress are considered a sharp rebuke to Obama, who is slated to give a speech Thursday on the future of Guantanamo Bay.
Obama, in one of his first official duties as president, announced that he would close the prison by January 22, 2010.
Congressional Democrats, however, are now attempting to avoid an onslaught of criticism from Republicans, who argue it would be reckless to shutter the prison before deciding where to transfer the detainees.
FBI Director Robert Mueller told members of Congress earlier Wednesday that he is concerned about the potential dangers that may result from the release of Guantanamo Bay detainees in the United States.
In response to a question from Texas Rep. Lamar Smith, the ranking Republican on the House Judiciary Committee, Mueller said he was concerned about the potential for fundraising to support terrorist groups and the radicalization of others, as well as the potential for attacks within the country.
Mueller also said that while he is not concerned about dangerous terrorists escaping from maximum security federal prisons, he is concerned about the potential of activities being directed from within prison walls, and he cited such actions by dangerous gang members.
Attorney General Eric Holder promised a Senate committee on May 7 he will not release suspected terrorists held at Guantanamo into the United States.
He was less clear about what would be done with any detainees the administration decides are not terrorists.
"We would not bring them into this country and release them, anyone we would consider to be a terrorist," Holder told the panel. He said the safety of the American public will be his "paramount concern."
–CNN's Terry Frieden contributed to this report