The US defence department has issued new instructions prohibiting physical or mental torture of prisoners.
The new directive is intended to prevent further abuse
The directive says all detainees shall be treated humanely and it specifically bans the use of dogs to intimidate those in custody.
It sets policy for all US military personnel and contractors, but does not cover other agencies, such as the CIA.
The US has been criticised by human rights groups over its treatment of detainees from Afghanistan and Iraq.
On Monday, the Pentagon announced that five more soldiers were being charged with abusing detainees in Iraq.
Pentagon spokesman Brian Whitman said this was the first time such a directive had been issued, pulling together the department's existing policies and memos covering the interrogation of detainees.
Another directive, to be issued in the future, will define exactly what is meant by humane, he added.
The new policy comes as the government's policy on detainees is under assault on a number of fronts.
A senior Republican senator, John McCain, is sponsoring legislation that would ban the abuse of detainees by law - a law the administration says it does not need.
In addition, the Supreme Court has said it will re-examine the legality of trying detainees in the Guantanamo Bay prison camp in front of military tribunals.
On Monday, President George W Bush defended his government's treatment of detainees after a media allegation that the CIA ran secret jails in eastern Europe.
"We do not torture," he told reporters during a visit to Panama.