Defense Secretary Robert Gates told a Senate panel Wednesday that he doesn't know if the 2002 authorization for the use of force against Iraq applies to ongoing operations there.

"I don't know the answer to that," Gates told Sen. Robert Byrd, D-W.Va., in response to his question asking if the authorization still applies.

"Well, sir, my impression is that it's the view of the president that it still continues to authorize the actions that we are taking in Iraq," Gates said, appearing before the Senate Appropriations Defense Subcommittee to answer questions about the Defense Department's budget.

President Bush indicated Wednesday that he would veto another Iraq supplemental bill if it would fund the war only into the summer months, White House spokesman Tony Snow said.

House Democrats are preparing to introduce a new war spending bill on Thursday that would pay for the war through July, and then give Congress the option of cutting off money after that if conditions in Iraq do not improve.

"There are restrictions on funding and there are also some of the spending items that were mentioned in the first veto message that are still in the bill," Snow said on Air Force One traveling with Bush to survey damage from a tornado in Greensburg, Kan.

Asked directly if Bush would veto the House bill in its current form, Snow said, "Yes."

Bush requested more than $90 billion to fund the war through September and vetoed one bill sent to him because it called for the withdrawal of troops starting by Oct. 1. The second bill is lacking a firm endorsement by the Senate, making the challenge appear to be more for political show than a preview of another veto showdown with Bush.

Gates said short-term funding would be very disruptive and "have a huge impact" on contracts to repair and replace equipment. The department doesn't "have the agility to manage a two month appropriation."

"It would have a devastating effect on the department," Defense Department spokesman Bryan Whitman said. "An institution of this size needs to have predictability and assurance" on the funding of its programs.

"It would be massively disruptive," Whitman said. "This is a large, complex institution."

Gates told the Senate panel that if the military begins to see progress in Iraq later this fall, including political reconciliation within the Iraqi government, the U.S. could begin withdrawing troops.

The Pentagon, he said, is "looking for the direction of events — we don't have to have it all locked in place and everything complete. ... If (we) see some very positive progress and it looks like things are heading in the right direction, then that's the point at which I think we can begin to consider reducing some of those forces."

He added that "getting the level of violence in Iraq to point where the political process can go forward and seeing some progress in reconciliation sets the stage for us to begin withdrawing our units ... and allowing those security responsibilities to be assumed by the Iraqis."

Back at the Pentagon, Lt. Col. James Hutton, public affairs officer for Lt. Gen. Raymond Odierno, second command in Iraq, said Odierno was misquoted by The Washington Post in saying the surge needs to continue until April.

"The surge needs to go through the beginning of next year for sure...." Odierno was quoted as saying in the Post. "What I am trying to do is to get until April so we can decide whether to keep it going or not."

But Hutton says it's not April, it's August and they contacted the Post to draw the reporter's attention to the mistake, which created concern on Capitol Hill that the Pentagon was not being up front about how long the surge will last. The Post stands by the story.

Senators asked Gates about this confusion and he told them Gen. David Petraeus would report back to them in September about progress in the surge.

Gates has said commanders in Iraq will provide as assessment of the conditions in Iraq in September. And he said Wednesday that the Iraqis are assuming more security responsibilities day by day, but the U.S. cannot abandon the country prematurely. Doing so, he said, would allow Al Qaeda terrorists to use Iraq's western Anbar province as a base to plan operations against the United States.

FOX News' Jennifer Griffin, Molly Hooper and Nick Simeone and The Associated Press contributed to this report.