Washington - President-elect Barack Obama is preparing to prohibit the use of waterboarding and other harsh interrogation techniques by ordering the CIA to follow military rules for questioning prisoners, according to two U.S. officials familiar with drafts of the plans. Still under debate is whether to allow exceptions in extraordinary cases.

    The proposal Obama is considering would require all CIA interrogators to follow conduct outlined in the U.S. Army Field Manual, the officials said. The plans would also have the effect of shutting down secret "black site" prisons around the world where the CIA has questioned terror suspects - with all future interrogations taking place inside American military facilities.

    However, Obama's changes may not be absolute. His advisers are considering adding a classified loophole to the rules that could allow the CIA to use some interrogation methods not specifically authorized by the Pentagon, the officials said. They said the intent is not to use that as an opening for possible use of waterboarding, an interrogation technique that simulates drowning.

    The new rules would abandon a part of President George W. Bush's counterterrorism policy that has been condemned internationally. Bush has defended his policies by pointing to the fact that the nation has gone more than seven years without another terrorist attack on its soil.

    Obama spokeswoman Brooke Anderson did not have an immediate comment Friday about the drafted plans, which the two officials discussed only on condition of anonymity because they were not authorized to comment publicly.

    No final decisions have been made about how to adjust the government's interrogation standards. Obama is still weighing whether to alter interrogation policy by executive order during his first days in office or to work with Congress through legislation.

    The plans do not specifically address the issue of extraordinary rendition, the policy of transferring foreign terrorism suspects to third countries without court approval.

    In private Capitol Hill meetings, CIA Director nominee Leon Panetta and Director of National Intelligence designate Dennis Blair have said Obama wants a single set of rules for interrogations. And in Senate testimony Thursday, Attorney General nominee Eric Holder called the Army manual "a good place to start."

    The 384-page Army manual, last updated in September 2006, is a publicly available document. It authorizes 19 interrogation methods used to question prisoners, including one allowing a detainee to be isolated from other inmates in some cases. The manual explicitly prohibits threats, coercion, physical abuse and waterboarding, which creates the sensation of drowning. Holder termed waterboarding a form of torture on Thursday.

    The CIA also banned waterboarding in 2006 but otherwise has been secretive about how it conducts interrogations. In the past, its methods are believed to have included sleep deprivation and disorientation, stress positions and exposing prisoners to uncomfortable cold or heat for long periods. It's also believed that some prisoners have been forced to sit in cramped spaces with bugs, snakes, rats or other vermin as a scare tactic.

    Waterboarding has been traced back hundreds of years and is condemned by nations worldwide. Hayden acknowledged last year that the CIA waterboarded three top al-Qaida operatives - including 9/11 mastermind Khalid Sheik Mohammed - in 2002 and 2003 because of fears that more attacks were imminent.

    The Army manual can be amended by the military. It is unclear whether the CIA would be held to the one published in 2006 or future versions.

    The military rejected adding a classified annex to the manual before it was published in 2006 because it believed having two sets of rules could confuse soldiers and reasoned that the classified techniques would quickly become known once those interrogated were released. A classified annex would also complicate sharing the manual with foreign governments and would undermines the military's goal of full transparency after Abu Ghraib.

    For Obama, who repeatedly insisted during the 2008 presidential campaign and the transition period that "America doesn't torture," a classified loophole would allow him to follow through on his promise to end harsh interrogations while retaining a full range of presidential options in conducting the war against terrorism.

    The proposed loophole, which could come in the form of a classified annex to the manual, is designed to satisfy intelligence experts who fear that an outright ban of so-called enhanced interrogation techniques would limit the government in obtaining threat information that could save American lives. It would also preserve Obama's flexibility to authorize any interrogation tactics he might deem necessary for national security.

    However, such a move would frustrate Senate Democrats and human rights, retired military and religious groups that have pressed for a government-wide prohibition on methods they describe as torture.

    Glenn Sulmasy, an international law professor at the U.S. Coast Guard Academy in New London, Conn., said Obama can and should preserve his executive authority to order aggressive interrogations when necessary. But he said that should be done on a case-by-case basis and not become a broad policy.

    "There are some coercive techniques that he might employ on a ticking time bomb scenario, but he'll distinguish himself by making it clear that the presumption under the law is that there is no torture," Sulmasy said Friday.

    Critics, however, said Obama cannot claim to ban torture if it's not clear what interrogation methods will be allowed.

    "That would not be good," said the Rev. Richard Killmer, executive director of the National Religious Campaign Against Torture. "We don't need to be able to torture and we don't need to engage in any interrogation techniques that are not humane. And unless we have absolute clarity that these interrogation techniques will not be used, they are not going to be able to say that."

    Speaking with reporters Thursday, outgoing CIA Director Michael Hayden said harsh interrogation tactics have been needed to get information from the most hardened terror suspects. He and some other U.S. intelligence officials oppose limiting the CIA to the Army manual, which was written specifically for military interrogations and may not be effective on the most dangerous detainees.

    "It is an honest discussion to talk about what techniques we should use, but to assume automatically that the Army Field Manual would suit the needs of the republic in all circumstances is a shot in the dark," Hayden said.

    Senate Democrats aren't likely to support a classified annex. Holder on Thursday said the interrogation methods outlined in the Army manual would be just as effective as those used by the CIA.

    "I'm not convinced at all that if we restrict ourselves to the Army field manual that we will be in any way less effective in the interrogation of people who have sworn to do us harm," Holder said.

    Amnesty International, the human rights group, on Friday hailed word that the field manual would extend to the CIA but said it would oppose a classified annex.