By Sean Lengell

Gen. David H. Petraeus on Tuesday softened Obama administration rhetoric that a U.S. troop withdrawal from Afghanistan would begin in July 2011, telling a Capitol Hill panel that such a move would be “based on conditions.”

“July 2011 is not the date where we race for the exits,” the general told the Senate Armed Services Committee. “It is the date where, having done an assessment, we begin a process of transition of tasks to Afghan security forces.”

Gen. Petraeus gave the testimony moments before he slumped at the witness table and excused himself from the room. The general returned about 20 minutes later, but committee Chairman Carl Levin, Michigan Democrat, postponed the rest the hearing.

A spokesman for Gen. Petraeus, commander of U.S. Central Command, which oversees all U.S. forces in Afghanistan, said the general was likely dehydrated and jet-lagged from recent travels.

Mr. Levin, prior to adjourning the hearing, asked the general whether the president’s promise to begin withdrawing troops by July 2011 “represent[ed] your best personal professional judgment.”

After a pause, the general said that “in a perfect world, Mr. Chairman, we have to be very careful with timeliness.”

Gen. Petraeus said that, like the withdrawal of U.S. troops in Iraq that began months ago, the drawdown in Afghanistan would be based on predetermined conditions.

“We are assuming that we will have those kinds of conditions [in Afghanistan] that will enable that by that time in July 2011,” he said. “That’s the projection. And that is what again we have supported.”

Sen. John McCain of Arizona, the committee’s top Republican, questioned the wisdom of establishing a withdrawal timeline, saying that it could convince “the key actors inside and outside of Afghanistan that the United States is more interested in leaving than succeeding in this conflict.”

“As a result, they’re all making the necessary accommodations for a post-American Afghanistan,” Mr. McCain said.

Gen. Petraeus, in response to Mr. McCain, reiterated that his goal is for a “responsible drawdown of our forces.”

President Obama announced in December that 30,000 additional military personnel would be sent to Afghanistan this year. Almost 21,000 have been deployed, which is slightly ahead of schedule, the general said.

The president at the time said the troop surge would allow the U.S. and its allies to accelerate their goal of handing over security responsibilities to Afghan forces and would “allow us to begin the transfer of our forces out of Afghanistan in July of 2011.”

The president added that, “Just as we have done in Iraq, we will execute this transition responsibly, taking into account conditions on the ground.”

Defense Secretary Robert M. Gates, while visiting Afghanistan in March, said that some of the troops involved in the surge could be withdrawn before July 2011, though he added that those decisions would be “conditions-based.”

Gen. Petraeus said the recent troop surge has helped stabilize Afghanistan, particularly in former Taliban strongholds in the south.

The general added that efforts to increase the size and capability of the Afghan army and police are “now on track,” though he said there “clearly is considerable work to be done in that critical area and to sustain the gains that have been made recently in recruiting and attrition.”

The general also said he disagreed with comments by Afghanistan’s former intelligence chief, Amrullah Saleh, in a recent New York Times interview that Afghan President Hamid Karzai has lost confidence in the ability of the U.S. and its coalition to succeed in the country.

Gen. Petraeus said that Army Gen. Stanley A. McChrystal, NATO’s commander in Afghanistan, spent Sunday with Mr. Karzai and that “there was certainly no sense on Gen. McChrystal’s part, nor on those of the others who were with him, that there was a lack of confidence in the United States commitment to Afghanistan.”

*This story is based in part on wire service reports.