A specially commissioned task force is said to be considering a call for a major change in US policy on Iraq.
US casualties are increasing the political pressure for change
The panel, which is led by former US Secretary of State James Baker, is said to think that "staying the course" is an untenable long-term strategy.
A senior US official has reaffirmed Washington's support for Iraq's leaders but said they must increasingly assume responsibility for security.
The Iraq situation is a key issue in November's US mid-term elections.
In a separate development UK Prime Minister Tony Blair has said that British forces will not "walk away" from Iraq or Afghanistan until their job there is done.
To pull out would leave enemies and extremists "heartened and emboldened", he told his monthly press conference.
His comments come just days after the head of the British army General Sir Richard Dannatt warned that UK troops "exacerbated" Iraq's security problems and should withdraw "sometime soon".
Invitation to help
Mr Baker's commission, which is due to report in the next few months, is reportedly considering significant changes.
The bipartisan task force, which was asked by the US Congress to examine the effectiveness of American policy in Iraq, has reportedly been looking at two options, both of which would amount to a reversal of the Bush administration's stance.
One is the phased withdrawal of US troops, and the other is to increase contact with Syria and Iran to help stop the fighting in Iraq.
"There's got to be another way," is how one member of the Iraq panel summed up their views on the situation in Iraq and the failure of current US policy, according to the LA Times.
October has seen another surge in violence
Referring to Mr Baker's report, Mr Blair said he would be "absolutely astonished" if it set out plans to "get out of Iraq come what may".
Mr Baker, who was secretary of state under President George Bush, the current president's father, has so far stressed that the panel has not come to a definitive conclusion.
But he has indicated the direction of the panel's thinking in recent television interviews.
"Our commission believes that there are alternatives between the stated alternatives, the ones that are out there in the political debate of 'stay the course' and 'cut and run,'" he told ABC News recently.
On Monday, President George W Bush called Iraqi Prime Minister Nouri Maliki to reaffirm his full support for the Iraqi government.
White House spokesman Tony Snow said Mr Bush had urged Mr Maliki to ignore rumours that Washington had set a deadline for the Iraqi government to control the activities of insurgents.
Deputy Treasury Secretary Robert Kimmitt has also stressed that the US government strongly supports Mr Maliki's strategy.
"Mr Maliki said first...there has to be improvement in the security situation, violence is absolutely unacceptable. Secondly, there has to be political reconciliation, and third there must be economic development... they're all inter-related," he told the BBC on Tuesday.
But he also said it was clear that the Iraqis must increasingly take control of security.
" I think... what my former boss, Jim Baker, said is that there needs to be over time steady assumption of increasingly responsibility by the Iraqis for their own future. I don't think anybody disagrees with that," Mr Kimmitt said.
As the key 7 November mid-term elections near, opinion polls have indicated growing public discontent with the Iraq war, a discontent that could have a significant impact on the election outcomes.
The Baker panel is not expected to make its recommendations public before the elections.
BBC News website world affairs correspondent Paul Reynolds says the panel's findings could be the peg on which a shift of approach is hung.
Since the March 2003 invasion, some 2,761 US military personnel have died in Iraq.