The Pentagon is moving ahead with scheduled troop deployments to Iraq next month as the U.S. military struggles to gain control of the escalating violence in Baghdad, according to a senior defense official.

The decision caps weeks of internal discussions about whether to delay or cancel the deployment of any units, which would have signaled an accelerated withdrawal of U.S. troops. It also underscores the difficulties in quelling the sectarian fighting and reflects remarks by the top U.S. commander in Iraq that he may shift more soldiers into Baghdad.

The military's current sentiment is to keep the status quo in Iraq, rather than moving toward a withdrawal that might be ill-advised considering the violence between the Sunnis and Shiites, the senior defense official said.

CountryWatch: Iraq

As units in Iraq prepare for their scheduled departure, military leaders had considered not sending all of the units that had been planned to replace them. But that idea has been put on hold, at least for now, according to the official.

The official spoke on condition of anonymity because discussions about troop decisions were private.

The move comes as Iraqi Prime Minister Nouri al-Maliki prepares to make his first official visit to the United States, during which he is expected to talk about the progress being made by his 2-month-old national unity government.

Next week's high-profile visit could refocus Congress' attention on Iraq after a week consumed by the violence in Lebanon and Israel. And it will bring troop levels once again to the forefront in a nation becoming increasingly impatient with the war in Iraq -- and a Congress eyeing its potential impact on the November elections with growing unease.

The past week was one of the most violent in Baghdad this year. Bombings and shootings soared by 40 percent, U.S. military spokesman Maj. Gen. William Caldwell said. Extremists were preparing "an all-out assault" on the capital in a decisive battle for the future of Iraq, he said.

Thousands more troops have been summoned to the capital to help quell the violence, and the top commander there, Gen. George Casey, said the U.S. would make sure "there are adequate forces available for the Iraqis to succeed in Baghdad."

During a visit to Iraq last week, Defense Secretary Donald H. Rumsfeld said political reconciliation between Sunnis and Shiites is as important as the military effort in establishing security in Iraq. And he said it was too early to estimate when overall levels of U.S. forces in Iraq might begin to fall.

Rumsfeld and others have said repeatedly they will make decisions about troop levels based on conditions on the ground, and they have refused to be held to a timeline.

Among the units scheduled to deploy to Iraq later this summer are the 3rd Brigade, 82nd Airborne Division, out of Fort Bragg, N.C., and the 2nd Brigade, 10th Mountain Division, out of Fort Drum, N.Y.

There are about 127,000 U.S. troops in Iraq, and military leaders have said they hoped to reduce that to about 100,000 by year's end. U.S. troop levels in Iraq have dropped from a peak of about 160,000 late last fall.

But in a reflection of the increasing violence, one brigade that had been stationed in Kuwait as a reserve force earlier this year is now almost entirely in Iraq, and at least one of its battalions was sent to Baghdad to bolster security.