Retired US general Mr Jay Garner will convene a meeting of 300 to 400 leading Iraqi political, religious and ethnic figures in Baghdad later today.
Mr Garner, charged by Washington with overseeing the rebuilding of Iraq, sought to reassure Iraqis they would determine their own political destiny in a radio broadcast yesterday.
"I will be here for just a short time, just to help get things going. This is your country and it's your future," he said.
Ms Barbara Bodine, Mr Garner's coordinator for central Iraq, said pro-American Mr Ahmad Chalabi, leader of the Iraqi National Congress umbrella group, had been invited to the meeting, along with the country's main Shi'ite Muslim group - the Supreme Council for the Islamic Revolution in Iraq.
Ms Bodine said the Baghdad meeting would have "more of an indigenous representation" than an April 15th meeting in Nassiriya.
A senior aide said the meeting would be used to identify potential leaders and discuss forming a new government.
Yesterday, US forces arrested the self-appointed mayor of Baghdad for trying to run the city without their authority and took him out of the capital.
Mr Mohammed Mohsen Zubaidi, a former exile who declared himself mayor 10 days ago, was "removed" from Baghdad for obstructing efforts to get Iraqis back to work after the war that ousted Saddam Hussein, a US military statement said.
The military also reported it had detained Gen Hussam Mohammad Amin, a key figure in talks with the UN inspectors who had hunted for banned Iraqi weapons before the war.