ARLINGTON, Va. — Commanders in Iraq are drawing up a plan to withdraw U.S. troops to “pre-surge levels” at the rate of about one brigade per month, which would keep the last of the surge troops in the country until August, Army Lt. Gen. Ray Odierno said Friday.

“What I’m talking about is drawing down to pre-surge levels,” Odierno, who is commander of the Multi-National Corps–Iraq, told Pentagon reporters a televised briefing from Baghdad.

“We’ll do it pretty much along the way they came in,” he said.

“The one thing we’ve dedicated to our soldiers is you’ll not be here longer than 15 months,” Odierno said. “So we know that the surge brigades will leave at 15 months. So that will be somewhere between April and August of ’08 when units will leave, based on the 15-month rotation.”

Odierno’s comments were the most detailed explanation to date of how U.S. military commanders are envisioning drawing down the number of brigade combat teams in Iraq back to the normal base level of 15, instead of the 20 brigades now deployed as a result of the buildup known as the “surge.”

In January, President Bush announced he was sending five additional brigades to Iraq, amounting to about 21,500 troops, in an effort to boost security.

The additional troops began arriving in Iraq in January, settling in at the rate of about one per month, with the last of the surge brigades in place in Baghdad in June, having deployed in May.

In his initial announcement of the surge Bush did not specify how long the additional troops would remain deployed, other than to say the commitment would not be open-ended.

As late as June 21, with the final surge brigade just beginning its operations, Defense Secretary Robert Gates told Pentagon reporters he couldn’t say how long U.S. forces would have to stay at increased levels in the effort to secure the country.

“I think that we’ll just have to wait and see the progress of these offensives,” Gates said.

Gates added that he was also waiting for the September progress report on the “surge” by Army Gen. David Petraeus, the top U.S. commander in Iraq.

On Thursday, Army Lt. Gen. Carter Ham, the Joint Staff’s director for operations, told reporters that while final decisions on troop levels will rest on Odierno’s report, the Defense Department is “planning to maintain the current levels until spring of ’08.”

“That’s the point at which the first of the so-called ‘surge brigades’ expires,” Ham said.

Military planners are now looking not at how long to keep the surge troops in Iraq, but “whether there will be anyone to backfill,” or replace, those units, Odierno said. “Right now, our plan is not to backfill those units. But Gen. Petraeus … will make those assessments.”

Both Ham and Odierno said that there are no plans to extend active-duty Army troops currently on 15-month tours to Iraq.

In fact, Odierno said he worries about the effects of 15-month tours on his troops and their families, particularly considering the fact that so many servicemembers are on their second or even third deployments.

“Fifteen months is a long time,” Odierno said. “None of us will deny it. It’s a long time in a stressful situation.”

Stars and Stripes reporter Jeff Schogol contributed to this story.