America's top military officer said Sunday the push for quick answers to an alleged massacre by U.S. Marines of Iraqi citizens in Haditha should not be allowed to outweigh the need for a thorough investigation.

Gen. Peter Pace, chairman of the Joint Chiefs of Staff, acknowledged that the allegations involving the deaths of about two dozen Iraqis have raised concerns among Iraqi officials and in the United States.

"But you don't want to have the emotions of the day weigh into the process," Pace told The Associated Press in an interview. "We need to stick with our judicial process. We want to be sure that it moves forward without any influence."

CountryWatch: Iraq

Pace said it is not clear exactly what happened last November when as many as two dozen Iraqis were killed during a U.S. attack.

U.S. military investigators have evidence that points toward unprovoked murders by the Marines, a senior U.S. defense official said last week.

Over the weekend, Pace joined U.S. Defense Secretary Donald H. Rumsfeld at a conference of defense leaders in Southeast Asia. In some countries in the region with sizable Muslim populations, the war in Iraq has soured attitudes toward the U.S.

The killings in Haditha have contributed to that, leading the U.S. military on Thursday to order that the 150,000 coalition troops in Iraq, including 130,000 Americans, get special training in ethics and "the values that separate us from our enemies."

The additional instruction, Pace said, "should provide comfort to those looking to see if we are a nation that stands on the values we hold dear."

U.S. troops should benefit from the additional training, particularly as they run through various battle scenarios, Pace said. "Emotions on the battlefield are intense," Pace said. "It's good to stop and check your moral compass."

Pace, the first Marine to serve as Joint Chiefs chairman, is no stranger to such combat emotions. To this day he keeps a photo on his desk at the Pentagon of the first Marine killed under his command when he was a platoon leader in Vietnam.

According to Barney Barnes, one of the men who served with Pace, Pace's first inclination was to call in the artillery "and bomb the heck out of that village." Barnes said Pace instead kept his emotions in check and searched the village — ultimately in vain — for the sniper whose bullet had killed Cpl. Guido Farinaro.

In the AP interview, Pace said those serving in the military need to train for combat situations and "to know what you're going to do."

In addition to the renewed ethics training for coalition troops in Iraq, U.S. Marine Commandant Gen. Michael W. Hagee has been talking to Marines about proper conduct on the battlefield.

Hagee last week spoke to troops about the danger of becoming "indifferent to the loss of a human life."

To Pace, "It's a very good thing to take an operational pause and talk about what we do and what we do not do in combat."

Pace has declined to talk about the specifics of the two investigations into the Haditha killings. He said Sunday he does not know when they will be completed. Both he and Rumsfeld have said they do not want to make comments that might taint the probes.

The investigation that will be finished first is the one examining whether the Marines in Haditha or their commanders tried to cover up what happened, Pace said. The second, a criminal investigation, will take longer.

The results of both investigations will be made public as soon as possible without interfering with the legal process, Pace pledged.

"Regardless of the outcome of these investigations, 99.9 percent of the servicemen and service women are doing what we expect them to do," he said.

Haditha, about 140 miles northwest of Baghdad, has been plagued by insurgents. On Nov. 19, a bomb rocked a military convoy, killing a Marine. Residents said Marines then went into nearby houses and shot members of two families, including a 3-year-old girl.

At first, the U.S. military described what happened as an ambush on a joint U.S.-Iraqi patrol, with a roadside bombing and subsequent firefight killing 15 civilians, eight insurgents and a Marine. The statement said the 15 civilians were killed by the blast, a claim the residents strongly denied.