Washington ? Administration officials are preparing long-range plans for indefinitely imprisoning suspected terrorists whom they do not want to set free or turn over to courts in the United States or other countries, according to intelligence, defense and diplomatic officials.

The Pentagon and the CIA have asked the White House to decide on a more permanent approach for potentially lifetime detentions, including for hundreds of people now in military and CIA custody whom the government does not have enough evidence to charge in courts.

The outcome of the review, which also involves the State Department, also would affect those expected to be captured in the course of future counterterrorism operations.

“We’ve been operating in the moment because that’s what has been required,” said a senior administration official involved in the discussions, who said the current detention system has strained relations between the United States and other countries. “Now we can take a breath. We have the ability and need to look at long-term solutions.”

One proposal under review is the transfer of large numbers of Afghan, Saudi and Yemeni detainees from the military’s Guantanamo Bay, Cuba, detention center into new U.S.-built prisons in their home countries. The prisons would be operated by those countries but the State Department, where this idea originated, would ask them to abide by recognized human rights standards and would monitor compliance, the senior administration official said.

As part of a solution, the Defense Department, which holds 500 prisoners at Guantanamo Bay, plans to ask Congress for $25 million to build a 200-bed prison to hold detainees who are unlikely to ever go through a military tribunal for lack of evidence, according to defense officials.

The new prison, dubbed Camp 6, would allow inmates more comfort and freedom than they have now, and would be designed for prisoners whom the government believes have no more intelligence to share, the officials said. It would be modeled on a U.S. prison and would allow socializing among inmates.

“Since global war on terror is a long-term effort it makes sense for us to be looking at solutions for long-term problems,” said Bryan Whitman, a Pentagon spokesman. “This has been evolutionary, but we are at a point in time where we have to say, ‘How do you deal with them in the long term?”‘