The U.S. military force in Iraq formally completed a realignment Saturday that is intended to allow the top commander to focus on developing Iraq's security forces while shifting responsibility for battling insurgents to his top deputy.

Lt. Gen. Ricardo Sanchez will remain the commander of U.S. forces in Iraq, the post he has held since last June. Lt. Gen. Thomas F. Metz will take the lead role in analyzing intelligence and improving tactics to combat attacks by guerrillas and militiamen opposed to the U.S.-led occupation.

The shift takes place just six weeks before the scheduled transfer of limited political power to an interim Iraqi government. A key goal of the Bush administration before the June 30 handover is to develop Iraqi army, paramilitary and police forces capable of quelling violent unrest and defending a new democratic government.

Defections, poor leadership and supply shortages have repeatedly set back that goal over the past year. Maj. Gen. David H. Petraeus, the former commander of the 101st Airborne Division, was reassigned to Iraq last month to oversee the training of the security forces. He reports directly to Sanchez.

After a ceremony Saturday marking the shift, Sanchez said he would focus on "issues at the strategic level, working with the senior leadership of the military and the government, and General Metz will now be in charge of the tactical battle and ensuring that we succeed out on the battlefield across the whole country."

Metz said the shift will take him away from the logistics, financial and personnel responsibilities he had as Sanchez's deputy. "As a commander, I will be much more involved in the operational and intelligence part of the battle," he said.

The ceremony marking the shift was held at the al-Faw Palace, which was built by former president Saddam Hussein as a leisure home and now serves as the headquarters of the U.S. military command. Before a crowd of Iraqi and foreign dignitaries that included the U.S. administrator of Iraq, L. Paul Bremer, Sanchez recalled that "hundreds of Iraqi patriots of the Iraqi security forces have fallen alongside of the coalition warriors as they too answered Iraq's call to arms."

He added, "With so many willing to sacrifice so much, there is no doubt democracy will succeed in Iraq."

Under the reorganization, which officials said had been planned for six months, the U.S.-led military force in Iraq -- formally known as Combined Joint Task Force 7 -- has been replaced with a new body called Multinational Force Iraq, commanded by Sanchez, and a subordinate entity, Multinational Corps Iraq, led by Metz.

The shift occurs as the military is wrestling with a continuing Shiite insurrection in southern Iraq and the massive blow inflicted by revelations of abuse and sexual humiliation of Iraqi detainees at the Army-run Abu Ghraib prison west of Baghdad. Seven soldiers face criminal charges in the scandal, and four courts-martial have been announced.

An investigation conducted by Maj. Gen. Antonio M. Taguba, while not explicitly criticizing Sanchez, faulted an order he signed Nov. 19 that placed authority at Abu Ghraib with the 205th Military Intelligence Brigade. Several of the charged soldiers, who are all reservists from a military police unit, have asserted that military intelligence operatives urged them to use rough tactics against prisoners.

Sanchez said the abuse scandal has prompted reflection within the ranks.

"There's all sorts of 20-20 hindsight when you look back," he said, adding: "Our institution is a training and learning organization. Every mission that we execute, we assess in its aftermath and we learn and we critique ourselves very, very thoroughly so that we can get better. We do that whether we're in peacetime or in wartime. This is another case where we're looking at ourselves very, very critically."

Sanchez declined to discuss the Nov. 19 order but said he did not feel he erred in his decisions on the command structure at Abu Ghraib. "The intent was right, the directives were proper, and I don't have any regrets at this point where I'd say 'This was wrong,' " he said.