General Miller was sent to Iraq last summer to recommend improvements in the intelligence gathering and detention operations there, a defense official said.

Mr. Bush has repeatedly said he ultimately wants to shutter the detention operations at Guantánamo.

The Army is planning to create 35 additional units specially trained in detention operations over the next three years.

For Mr. Cerda, the former acting director of immigrant detention operations, the saving grace was his relatively modest salary at the department.

Step three, he said, involves Iraqi guards taking the lead of detention operations under the supervision of the American forces.

Much of the conversation centered on Aamer's thoughts on the detention operation and what could be done to improve it.

He described Guantanamo as "...a safe, humane and professional detention operation..."

These detention facilities were constructed to provide detention, operations, and related services necessary for the protection of society.

A new immigration detention services group was established in 2011 to implement policy, manage contractors and coordinate detention operations.

Investigators determined that both conditions existed in American-run detention operations in Afghanistan and Iraq.