The 20 minute recording offered US troops a one-month truce to withdrawl from the country  without being attacked.  The authenticity of the tape could not be verified, but it was posted on two main Web sites used by al Qaeda and other insurgent groups in Iraq.

"We are anouncing our orders for you, so obey them before you regret it," Al Baghdadi says on the recording. "We are awaiting your response within two weeks of this announcement."

The recording was posted on the Internet hours after Defense Secretary Robert Gates ended a visit to Iraq aimed at finding a new strategy to curb violence and allow U.S. troops to withdraw.

"You (Bush) wasted the opportunity of the truce offered to you by the sheikh of the mujahideen, Osama bin Laden, may God protect him," said Al Baghadadi. In January, bin Laden warned in an audio tape that al Qaeda was preparing new attacks inside the United States, but said the group was open to a conditional truce with the Americans.

Washington has said it does not negotiate with terrorists.

Qaeda-backed group offers U.S. safe Iraq exit: Web