A senior U.S. military officer acknowledged Saturday that the Americans have not achieved their goals in Fallujah despite the agreement to end the siege of the Sunni Muslim (search) city and turn security over to an Iraqi force.

Ten U.S. Marines and hundreds of Iraqis were killed during the three-week siege of Fallujah, which was launched after four Americans working for the Blackwater USA (search) security company were ambushed, killed, their bodies mutilated and hung from a Euphrates river bridge.

Brig. Gen. Mark Kimmitt (search) told reporters that the city had been generally quiet since Marines lifted the siege in early May.

Kimmitt also said the U.S.-led coalition had demanded a return to Iraqi government control, handing over of heavy weapons and the arrest of those responsible for the killing of the Blackwater employees.

"We are not satisfied we are making active progress in the latter," Kimmitt said. "We are not satisfied that there has been progress on any of those objectives, with the exception of having Iraqi presence back inside the city."

Hard-line Islamic leaders have reasserted their power in Fallujah (search), 30 miles west of Baghdad. Some were active in defending the city against the Marines and have profited by a perception — both here and elsewhere in Iraq — that the Fallujah fighters defeated a superpower.