WASHINGTON (AP) -- A leading Republican senator said Sunday that the Bush administration is making "a terrible mistake" in opposing a congressional ban on torture and other inhuman treatment of prisoners in U.S. custody.Sen. Chuck Hagel, considered a potential presidential candidate in 2008, said many Republican senators support the ban proposed by Sen. John McCain, R-Arizona, a prisoner of war during the Vietnam War.The ban was approved by a 90-9 vote last month in the Senate and added to a defense spending bill. The White House has threatened a veto, but the fate of the proposal depends on House-Senate negotiations that will reconcile different versions of the spending measure. The House's does not include the ban.Vice President Dick Cheney has lobbied Republican senators to allow an exemption for prisoners held by the CIA if preventing an attack is at stake."I think the administration is making a terrible mistake in opposing John McCain's amendment on detainees and torture," Hagel, R-Nebraska, said on "This Week" on ABC. "Why in the world they're doing that, I don't know."McCain, citing the Senate vote as well as support from the public and from former Secretary of State Colin Powell and others with military service, said he will push the issue with the White House "as far as necessary.""We need to get this issue behind us," McCain said on "Fox News Sunday." "Our image in the world is suffering very badly, and one of the reasons for it is the perception that we abuse people that we take captive."Mistreatment of prisoners at Iraq's Abu Ghraib prison and allegations of mistreatment at the U.S.-run camp at Guantanamo Bay, Cuba, have drawn withering criticism from around the world. Human rights organizations also contend that the United States sends detainees to countries that it knows will use torture to try to extract intelligence information.When the White House failed to kill the anti-torture provision while it was pending in the Senate, it began arguing for an exemption in cases of "clandestine counterterrorism operations conducted abroad, with respect to terrorists who are not citizens of the United States."The president would have to approve the exemption, according to the administration proposal, and any activity would have to be consistent with the Constitution, federal law and U.S. treaty obligations.Sen. Orrin Hatch, R-Utah, said he supports the vice president's efforts to gain a CIA exemption. While contending that the administration opposes torture, Hatch said, "They're going to everything in their power to make sure that our citizens in the United States of America are protected."Appearing with Hatch on CBS's "Face the Nation," Sen. Dick Durbin, D-Illinois, said cruel, inhuman and degrading treatment of prisoners "is not what America is all about. Those aren't the values that we're fighting for."Sen. Pat Roberts, the Kansas Republican who chairs the Senate Intelligence Committee, said his vote against the ban doesn't mean he favors torture. He rejected Durbin's comments as "not really relevant to what we are trying to do to detain and interrogate the worst of the worst so that we can save American lives."Roberts said that success with detention and interrogation depends on the detainee's fear of the unknown. He suggested that passing a law and putting U.S. policies into a manual would tell detainees too much about what to expect."As long as you're following the Constitution and there's no torture and no inhumane treatment, I see nothing wrong with saying here is the worst of the worst. We know they have specific information to save American lives in terrorist attacks around the world. That's what we're talking about," Roberts said.Copyright 2005 The Associated Press. All rights reserved.This material may not be published, broadcast, rewritten, or redistributed.