By Patricia Zengerle
WASHINGTON (Reuters) - Republican lawmakers have unveiled plans to make it harder to transfer inmates from the Guantanamo Bay Naval Base, stepping up a campaign to slow President Barack Obama's efforts to close the controversial detention center.
The proposed 2016 National Defense Authorization Act released on Monday renewed an annual ban on spending to transfer prisoners to the United States from the detention center.
The bill added new restrictions, including rescinding Obama's authority to unilaterally transfer detainees. It would require that any transfer take place only when the Secretary of Defense could certify that a country receiving prisoners would maintain control over them to ensure they cannot threaten the United States.
And it bars the transfer of detainees to combat zones, after some were sent home to Afghanistan.
Including those measures in a final defense bill could lead to a presidential veto. The White House has threatened to veto legislation passed by the Senate Armed Services Committee that would bar transfers from Guantanamo until after Obama's presidency.
The detention center was opened in the wake of the Sept. 11, 2001 attacks, by then-President George W. Bush, a Republican, to house terrorism suspects. It has been widely criticized because many prisoners were captured and held for years, far from their families, without being charged with any crime.
Obama, a Democrat, promised to shut the prison when he took office in 2009 but has been unable to do so, partly because of obstacles posed by Congress. But 116 detainees have been transferred, repatriated or resettled since he took office, worrying lawmakers who fear they might return to the battlefield.
There are 122 detainees at the base, of whom 106 have been held for more than 10 years. Nearly half, 57, of those still at the detention center have been approved for release.
The divide between the White House and Congress widened in 2014 after Obama released five Taliban members from Guantanamo in exchange for captured U.S. Army Sergeant Bowe Bergdahl without giving Congress the required 30-day notice.
Republican Mac Thornberry, chairman of the House Armed Service Committee, who released the proposed bill on Monday, said he is frustrated with the administration's failure to provide information about the transfer.
Until that material is provided, Thornberry proposed withholding 25 percent of funding for the Office of the Secretary of Defense.