A senior United States official, on condition of anonymity, said the report by weapons inspector David Kay is expected to report finding "documentary evidence" of Iraqi chemical and biological weapons programmes, but no proof of the arms themselves.
The Kay report "generally will be about chemical and biological weapons and I think he's going to find evidence, documentary evidence, statements by Iraqi scientists and technicians, that they had chemical and biological weapons production programmes," the official said.
"Whether they will find or disclose anything on the weapons themselves, I doubt," he added.
US national security adviser Condoleezza Rice warned it was too soon to say what US and British arms inspectors scouring Iraq for evidence of weapons of mass destruction will say in a forthcoming report.
"I think that it is premature for anybody to start saying what is or is not in that report," Rice said in a briefing to reporters.
"Whether they will find or disclose anything on the weapons themselves, I doubt"
Unnamed US official
Former weapons inspector David Kay, who leads the 1,400-strong Iraq Survey Group, "is still in the process, with some people in the intelligence community, of developing that report," Rice said. Kay served as a United Nations nuclear inspector in Iraq in 1991.
"My understanding is that it is a report that is very much a progress report and that doesn't rule anything out or anything in," Rice added.
"I would not jump to any definitive conclusions about what's in that report, and I think anybody who's doing that probably doesn't really know" what's in it, she said.
The CIA has described the Kay report as an initial document that will "reach no firm conclusions."