James Baker, secretary of state under George Bush Sr, the former US president, will announce the plan a few weeks after the November 7 congressional elections.
Options reportedly under consideration in Baker's plan are the phased withdrawal of US soldiers and the opening of dialogue with Syria and Iran.
Both of these options have been rejected in the past by Bush. Syria is viewed as a state sponsor of international terrorism by Washington, while Iran has faced US pressure due to its nuclear enrichment programme.
The Republicans of George Bush, current US president, risk losing control of Congress largely because of deep popular concern over Iraq.
Baker heads the Iraq Study Group, a bipartisan commission that since March has been researching and preparing ideas for changing course in Iraq.
"If our report is going to be worth anything, it has to be independent and it has to be our telling it like it is"
ex-US Secretary of State and head of the Iraq Study Group
"Everybody knows how close I am to the Bush family. But if our report is going to be worth anything, it has to be independent and it has to be our telling it like it is. And I'm here to tell you that's the way it's going to be, as far as I'm concerned," Baker said.
So far, Bush's strategy has been to support Nuri al-Maliki, Iraq's prime minister, in the hope he can overcome sectarian differences in the country.
However, Bush is under pressure to consider changes in the wake of a new wave of US military deaths. Ten American soldiers were killed on Tuesday.
The Iraq Study Group includes Baker as chairman and Lee Hamilton, a former Democratic representative, as co-chairman.
Other members represent a mix of important establishment figures from both parties in Washington.
"We will write our own report. It will not be written in the White House or in the Congress, and it will not be submitted to somebody to amend or modify," said Hamilton.
"This will be the report of the 10 members of the Iraq Study Group. We are going to be do our best to reach a consensus but I can't make a guarantee ... We will make foreign policy recommendations."
No 'full solution'
Baker has none the less warned against expecting a full solution to the Iraq crisis.
"We will write our own report. It will not be written in the White House or in the Congress"
co-chairman, Iraq Study Group
"It is very, very difficult," he told the World Affairs Council of Houston on Tuesday. "So anybody who thinks that somehow we're going to come up with something that is going to totally solve the problem, is engaging in wishful thinking."
Bush has been reluctant to make a major change in course in Iraq, seeing the conflict as a central front in the war on terrorism and insisting that to withdraw prematurely would embolden America's enemies.
Tony Snow, the White House spokesman, took a wait-and-see attitude about the Baker report. "This is something you listen to seriously, but we are not going to outsource the business of handling the war in Iraq," he said.