Iraqi Army forces may be able to take over the more volatile regions of their country by the end of this year, as long as they have the equipment and logistical support they need, the top U.S. military commander said Monday.

Marine Gen. Peter Pace, chairman of the Joint Chiefs of Staff, said that by year's end the Iraqi army will have recruited all of the units it needs, and the U.S. will have trained "a vast majority of their Army."

"Right now the Iraqis have [control] over half of Baghdad, and Baghdad is a pretty tough neighborhood, so they're certainly capable, regardless of the area, of being in control," Pace said in an interview on a military aircraft en route to Pakistan. "It will be just a matter of time to see what makes sense."

Pace's comments expanded on assertions made late last week by Army Lt. Gen. Peter Chiarelli, the second-ranking U.S. commander in Iraq, who said the goal is to have Iraqi security forces in control of 75 percent of the country's territory by the end of the summer.

Asked if that territory included the Anbar region and the Sunni Triangle, where much of the recent sectarian violence has been centered, Pace said that is a possibility.

He said the training of the Iraqi forces is going well, and "they will have sufficient numbers of troops to do that and then, like anything, for both coalition forces and Iraqi forces it will depend on how much of the anti-Iraqi activity is going on in any particular area."

Any significant U.S. withdrawal from Iraq depends on the ability of the Iraqi army to take control. The recent sectarian violence has raised questions about the fragile country's ability to form a unified government and stand on its own.

Pace's comments came as Iraqi and U.S. forces continued a sweep in the desert northeast of Samarra, trying to locate weapons caches and flush out insurgents.

The U.S. has about 133,000 troops in Iraq, and military officials have said they are still on track to reduce the U.S. presence there, as long as efforts to form a unified government continue.

Pace, Defense Secretary Donald H. Rumsfeld and others insist that the ongoing violence between religious groups in Iraq has not yet plunged the country into a civil war.

But the third anniversary of the U.S. invasion of Iraq is also marked by some of the lowest popularity numbers for President Bush, and a growing impatience with the war among Americans who increasingly say in polls that the administration's war policies are failing.

The administration also is under pressure from members of Congress, who have complained in recent weeks that they have yet to see the Pentagon's promised year of transition during 2006 in Iraq.

Pace arrived in Islamabad Monday and met with senior Pakistani defense officials, including his counterpart Gen. Ehsan Ul Haq, at the Pakistan Joint Staff Headquarters. He was greeted with full military honors, including a short parade of Pakistani service members and a band.

During the meeting the leaders talked about problems with terrorists along the border with Afghanistan, according to a senior U.S. defense official, who requested anonymity because the meeting was private. The Pakistanis said they are strongly committed to being effective partners with the U.S. in the war on terror, the U.S. official said.

Pace will also meet with U.S. military officials who are preparing to pull out the last 260 American troops who have been in Pakistan as part of the earthquake relief effort.

Parts of the country were devastated by a 7.6 magnitude earthquake last October that killed more than 80,000 people. All remaining U.S. military are expected to be out of Pakistan by the end of the month or early April.

At its peak, the U.S. had 1,200 personnel here, including hospital units, mobile construction battalions and other transport and relief units. Humanitarian flights delivered more than 20 million pounds of food, medical equipment and other supplies.

The disaster left about 3 million people homeless in the mountainous region.