Senior military sources in Iraq said Tuesday they have no intention of moving up an assessment on progress in Iraq from September nor will an interim report due this week suggest that the Iraqi government has failed to reach any benchmarks for success.

A spokesman to Gen. David Petraeus, the head of Multinational Forces in Iraq, told FOX News that the report that is due in September will be delivered in September. The remark was made following reports that Petraeus may deliver the report early in the face of growing impatience for the war on Capitol Hill.

"There is no moving up of the assessment from September," said MNF-I spokesman Col. Steven A. Boylan.

And according to a senior U.S. military source in Baghdad who has read a draft of the interim report to be delivered to Congress this week, it will show movement by the government in Iraq. The source added the benchmark report was never intended to measure if the Iraqi government has achieved the 18 benchmarks laid out for it but was only meant to assess the status of each of the specific benchmarks with a specific goal of declaring whether satisfactory or unsatisfactory progress was made toward meeting the benchmarks.

• FOX Facts: Benchmarks for the Iraqi Government

"I can assure you that we did assess some of the benchmarks as satisfactory progress," the source told FOX News.

"I don't think that is accurate as there has been some from my understanding that have either been met are are in progress, especially in the areas of security and movement in some of the legislative" activities, the individual added.

The July reporting requirements demanded by Congress call for an assessment of the status of each of the specific benchmarks and if the assessment notes any unsatisfactory progress, the president is to include in the report a description of such revisions to the political, economic, regional and military components of the strategy as well as advise on the appropriateness of implementing recommendations of the Iraq Study Group as deemed appropriate.

The interim report, required by law, is expected to be delivered to Capitol Hill by Thursday or Friday, as the Senate takes up a $649 billion defense policy bill and votes on a Democratic amendment ordering troop withdrawals to begin in 120 days.

This spring, Congress agreed to continue funding the war through September but demanded that Bush certify on July 15 and again on Sept. 15 that the Iraqis were living up to their political promises or forgo U.S. aid dollars.

The report that the U.S.-backed government in Iraq has not met any of its targets for political, economic and other reforms could vastly accelerate debate among President Bush's top aides on withdrawing troops and scaling back the U.S. presence in Iraq.

Already, presidential adviser Karl Rove is heavily involved in conversations with GOP senators attending meetings at the White House, two Senate leadership aides told FOX News, and is working to craft a message on how to begin to embrace a slow withdrawal of Iraq delineated by the ISG, if conditions on the ground don't improve by April 2008.

Rove told Republicans in a speech this weekend that the White House "will be redefining the mission, because the goal of the surge was to get us to a place where we could redefine the mission, to take it to something close to what Baker-Hamilton says, which is... to help protect the territorial integrity of Iraq." The ISG is led by former Secretary of State James Baker and former Indiana Rep. Lee Hamilton.

Bush administration officials have repudiated claims that the progress report to be delivered this week will show no progress toward meeting goals of the surge and benchmarks for political and legal progress by the Iraqi government.

"The report to be issued by Sunday will present a picture of satisfactory progress on some benchmarks and not on others," senior administration officials told FOX News Monday after another administration source reportedly said the Iraqi government will not have met one of its goals to reduce violence and improve living conditions of war-torn Iraqis.

"This is to be expected given the report is a preliminary snapshot of what are the early stages of the full surge," the official said.

Despite the tempered remarks, three senior Republican Senate aides confirmed to FOX News that the mid-July progress report on the Iraq troop surge will report zero benchmarks achieved by the Iraqi government.

One senior GOP leadership staffer anticipated a "brutal and ugly" few weeks of debate on Iraq, but was dismissive of the mid-July report's larger implications.

"It's not surprising," he said. "We knew they haven't passed the oil law yet. We knew they haven't passed debaathification. Did anyone really expect the interim report would say anything else?"

White House Press Secretary Tony Snow said Tuesday that the additional troops sent this year as part of a surge have just gotten in place and it would be unrealistic to expect major progress by now.

"There are a lot of discussions about everything," he told NBC's "Today" show. "We're now about two weeks into having the surge operational. What we want to see now is whether the surge is working. We're at the starting point now."

One Pentagon official said it would not be surprising "if the report comes out saying that the Iraqi government has not met any of the benchmarks."

However, the official said the report is "not a useful way of judging what is happening right now in Iraq" because "the Congress set a high bar for these benchmarks. The way the benchmarks are written does not give much wiggle room in signing off on whether the goals have been met or not."

Another senior U.S. official could not confirm the details of the report, but said if the U.S. government thought the Iraqi government was capable of meeting its benchmarks by July, then the United States would not have emphasized the importance of September. The official said there was no expectation the Iraqis would be meeting many of these goals by July.

While some of the benchmarks are obvious such as passing specific laws, this official said others are vague and the Iraqis may be making gradual achievement in a number of areas. This movement may not be measured by the benchmarks in this July report.

"It's not like one day the Iraqi security forces are bad and then there comes a day when they are suddenly satisfactory. It is evolving. July is too early to judge whether the surge is working," the Pentagon official said.

Regardless of the report, several Republican senators have already signed on with Democrats to declare a need for an end to the war. Sen. Olympia Snowe, R-Maine, a moderate who has been moving toward withdrawal, told FOX News that it may be time for Congress "to move from a nonbinding to a binding approach" on Iraq, and she is actively considering voting for a mandatory beginning of a drawdown within 120 days of bill passage.

On Monday, former Army Ranger, Sen. Jack Reed, D-R.I., told reporters that he suspects that Petraeus is preparing to deliver his briefing on Iraq before the Sept. 15 deadline and will take into account that U.S. forces can not be sustained beyond the spring of 2008. Aside from that, he said the U.S. public may not continue to support the mission.

"The ability to sustain this level of troops in Iraq probably gets very difficult come next spring. April is the timeframe that I've heard discussed as being very difficult to support this level without extending tours, without doing lots of things that are going to be extremely difficult," Reed said.

"I think the second issue too, which they're acutely aware of, and which (Gen. Petraeus) and both the ambassador are, is that in order to sustain any policy, you have to have strong public support. And that support today is weakening significantly. And I think the American public are looking for a change in direction, and I think that is part of the consideration," Reed said.

A Bush administration official said the "pivot point" for addressing the matter will no longer be Sept. 15, as initially envisioned, when a full report on Bush's so-called "surge" plan is due, but instead will come this week when the interim mid-July assessment is released.

"The facts are not in question," the official told The Associated Press, speaking on condition of anonymity. "The real question is how the White House proceeds with a post-surge strategy in light of the report."

The Pentagon official said the effectiveness of Iraqi troops is evolving and it is still too early in the strategy to label its success or failure.

"It's not like one day the Iraqi security forces are bad and then there comes a day when they are suddenly satisfactory," the Pentagon official told FOX News. "July is too early to judge whether the surge is working."

Meanwhile, Sen. Susan Collins and Democratic Sen. Ben Nelson introduced a binding amendment that would require U.S. troops to abandon combat missions. Collins and Nelson say their binding amendment would order the U.S. mission to focus on training the Iraqi security forces, targeting Al Qaeda members and protecting Iraq's borders.

"My goal is to redefine the mission and set the stage for a significant but gradual drawdown of our troops next year," said Collins.

Collins and five other Republican senators also support separate legislation calling on Bush to adopt as U.S. policy recommendations by the Iraq Study Group, which identified a potential redeployment date of spring 2008.

Republican support for the war has eroded steadily since Bush's decision in January to send some 30,000 additional troops to Iraq. At the time, Bush said the Iraqis agreed to meet certain benchmarks, such as enacting a law to divide the nation's oil reserves.

Sen. Jon Kyl, R-Ariz., chairman of Senate Republican Conference, requested and got an impromptu White House meeting Monday afternoon. Kyl did not see Mr. Bush but huddled with senior aides, emerging to say most Republicans would resist Democratic moves to de-authorize the war.

Kyl, along with several Republican stalwarts, including Sens. Ted Stevens of Alaska, Christopher Bond of Missouri and James Inhofe of Oklahoma, said they still support Bush's Iraq strategy.

Kyl said he would try to focus this week's debate on preserving vital anti-terrorism programs, including the detention of terror suspects at Guantanamo Bay in Cuba. The defense bill is on track to expand the legal rights of those held at the military prison, and many Democrats want to propose legislation that would shut the facility.

"If Democrats use the defense authorization bill to pander to the far left at the expense of our national security, they should expect serious opposition from Republicans," Kyl said.

As the Senate debate began, the Democratic Senatorial Campaign Committee arranged to run television commercials in four states, beginning Tuesday, to pressure Republicans on the war.

The boost in troop levels in Iraq has increased the cost of war there and in Afghanistan to $12 billion a month, with the overall tally for Iraq alone nearing a half-trillion dollars, according to the nonpartisan Congressional Research Service, which provides research and analysis to lawmakers.

The figures call into question the Pentagon's estimate that the increase in troop strength and intensifying pace of operations in Baghdad and Anbar province would cost $5.6 billion through the end of September.

FOX News' Jennifer Griffin, Major Garrett, Mike Emanuel and Trish Turner and The Associated Press contributed to this report.