A Pentagon troop withdrawal plan is among options being considered for Iraq, the White House said Monday. President Bush said U.S. troop levels will be determined by military commanders, the new Iraqi government and conditions on the ground.

Bush told reporters he would await a recommendation from Gen. George Casey, the top U.S. commander in Iraq. "And one of the things General Casey assured me of was that whatever recommendation he makes, it'll be aimed toward achieving victory," Bush said.

"And victory means a free government that is able to sustain itself, defend itself," Bush said. The president said he was briefed by Casey at the White House on Friday.

Bush brushed aside reports that Casey had plans for sending home two combat brigades, or about 7,000 of the 127,000 American troops there, by September without replacing them.

Tony Snow, Bush's press secretary, said later that such a plan was one of several under consideration.

"General Casey proposes lots of things and actually laid out more than one option. And everybody's fastening on one," Snow said. "Certainly that's under consideration, but I would warn against saying this is what he's saying, this is what he wants."

"When he makes a recommendation, the president's going to follow it. He trusts General Casey and he's made it clear," Snow said.

Remarks by the president and Snow followed a New York Times report Sunday that Casey's plan entailed bringing home about 7,000 U.S. troops by September and an additional 20,000 or more by the end of 2007.

Democrats cited stories on Casey's reported plan to criticize the White House and its allies in Congress.

Senate Minority Leader Harry Reid, D-Nev., urged his Senate colleagues "to note how similar General Casey's apparent plan to withdraw U.S. forces is to the plan put forward by Senate Democrats last week." That plan was rejected by majority-party Republicans.

"I wonder how the majority feels today, now that General Casey's plan is in the open?" said Reid. "Do they disagree with General Casey that we need to begin ending the open-ended commitment in Iraq? Do they still believe a plan for reducing our troops levels is defeatist and unpatriotic?"

Asked about Casey's purported plan, Bush only confirmed that he met with Casey on Friday and that "we talked about a lot of things."

"In terms of our troop presence there, that decision will be made by Gen. Casey as well as the sovereign government of Iraq, based upon conditions on the ground," Bush said.

"I've told the American people our commanders will be making the decisions as to how to achieve victory. And General Casey, of course, is the lead person," Bush said.

Bush said he and Casey also talked about the training of Iraqi security forces, the joint U.S.-Iraqi operation to secure Baghdad and conditions in rebellious Anbar province and its provincial capital of Ramadi.

"The coalition is in the lead in Ramadi and we're trying to make sure Ramadi does not become a safe haven for al-Qaida. And so he (Casey) explained to me the tactics on the ground, what we're doing to secure that city and to run the al-Qaida types out," Bush said.

Bush spoke with reporters after meeting with leaders of private organizations that support the U.S. military in Iraq.

Meanwhile, Pentagon spokesman Bryan Whitman said Casey talked both about positive trends that he's seeing in Iraq, and the issues that lie ahead.

"The challenges that he talked about are very real and somewhat unpredictable," said Whitman. "And because of that, there's going to need to be a certain amount of flexibility that the commander has, to adjust forces over time."

"There should not be hard and fast timetables associated with our force adjustments," said Whitman. "The commanders on the ground need the flexibility to be able to adjust the troop levels based on the conditions that exist."

Snow, the White House spokesman, refused to disclose what Casey told Bush but said the general has "a number of scenarios in mind for differing situations on the ground." He said planning would change based on conditions.

"But I'm certainly not going to announce in advance anything that he may have in mind for the president or that he may be recommending," Snow said. "Just don't do that in a time of war."