WASHINGTON (CNN) -- Pentagon officials told CNN on Monday they do not expect Gen. David Petraeus to recommend or predict additional U.S. troop cuts in Iraq when he testifies before Congress this week.
Gen. David Petraeus speaks to CNN's Kyra Phillips on March 19 in Baghdad, Iraq.
Nevertheless, some officials hope that by year's end, an additional brigade or two could be pulled out, according to an aide to a senior general.
Petraeus spent his last day before his scheduled "State of Iraq" report to Congress polishing his opening statement, which remains a closely guarded document, according to one of his top aides.
Petraeus, the commander of multinational forces in Iraq, and Ambassador Ryan Crocker will answer questions from key senators Tuesday and from House members Wednesday.
Several officials who talked to CNN said they expect Petraeus to avoid any prediction about additional troop withdrawals beyond the 20,000 U.S. troops returning home as the troop "surge" ends in July. Watch what Washington expects from Petraeus »
Any additional force reductions will be "conditions-based," according to one senior official, who noted Petraeus has consistently said that it's impossible to predict what conditions will be six months in advance.
Last month, Petraeus told CNN's Kyra Phillips that the military was in a "better place in terms of security, and even in terms of political progress by the Iraqis, than we were, say, a year ago, although we are always quick to note that the progress is tenuous and that it is reversible and that there are innumerable challenges out there." Watch more of Petraeus' interview »
At the end of March, a high-profile week of fighting erupted in Basra between Iraqi government forces and Shiite militias after months in which violence seemed to be declining. Military results were inconclusive.
The battle ended only after Iraqi Shiite lawmakers traveled to Iran to negotiate with Iranian leaders and Iraqi Shiite cleric Muqtada al-Sadr, who commands the loyalty of the largest militia in Iraq.
White House spokesman Tony Fratto admitted Monday the operation in Basra was not "an overall success" for Iraqi government forces.
While officials are eager to hear what Petraeus says in his two days of testimony, the general expectation is he will put off until fall any decision on additional troop cuts.
After the surge ends in July, there will be 15 U.S. combat brigade teams in Iraq, and roughly 140,000 American troops.
Last September, Defense Secretary Robert Gates floated the prospect of pulling five additional brigades out of Iraq by 2009.
And when Petraeus and Crocker last testified in September, Petraeus said he would be hard-pressed to recommend maintaining the surge of U.S. troops in Iraq past this spring if conditions in the country did not improve in the interim.
Since then, however, Petraeus has requested a "pause" in troop withdrawals following the end of the surge.
Now, officials say privately that the hope is that one or two brigades could leave before Christmas.
That may be possible because of plans to shorten Army combat-zone tours from 15 months to 12 months as of this summer. President Bush is expected to announce that change Thursday.
Crocker, meanwhile, is expected to take a positive view of political progress in Iraq.
Senior U.S. officials familiar with Crocker's deliberations said they expect him to point to slow but steady political progress, including better cooperation in parliament to meet and pass laws and a better working relationship within the three-member presidency council.
Crocker will also argue that Prime Minister Nuri al-Maliki is making more of an effort to work with Iraq's various factions and political parties, they said.
The ambassador is also expected to bring up "meddling" by Iran and will call for greater participation by Iraq's Arab neighbors, they said.
All three leading presidential candidates -- Democratic Sens. Hillary Clinton and Barack Obama, and Republican Sen. John McCain -- are scheduled to question Petraeus and Crocker on Tuesday.
In advance of this week's events, Democrats are charging once again they believe the war in Iraq has made the United States less safe.
"Based on everything we have heard so far, the president has no intention of bringing home any more troops anytime soon and is instead leaving the tough decisions to the next administration," said Jim Manley, a spokesman for Senate Majority Leader Harry Reid, D-Nevada. "In effect, he is going to kick the can down the road."
Reid and 46 of his Senate Democratic colleagues sent the president a letter Sunday demanding that he refocus the nation's counter-terrorism strategy on Afghanistan and Pakistan.
"While violence and the drug trade have surged in Afghanistan, and Pakistan's security remains fragile, we are distracted by an endless civil war in Iraq," Reid said in a prepared statement.
"To make America more secure, we must refocus on hunting down a resurgent al Qaeda, securing a troubled Afghanistan and rebuilding our overburdened and misused military."
White House officials responded that the administration is committed to victory in both Afghanistan and Iraq. E-mail to a friend
CNN's Jamie McIntyre, Barbara Starr, Nic Robertson and Ed Henry contributed to this report