The CIA and other US intelligence agencies are reviewing their pre-war views of Iraq.
The focus of the review, decided before the war, will be on answering the questions: "How did we do? What did we get right? What didn't we get right?" said the official.
The review comes at a time when the Bush administration faces increasing questions about the validity of the intelligence used to justify the invasion.
This includes the portrayal of Iraq as having large stockpiles of chemical weapons, its capability to rapidly produce biological weapons and a research programme aimed at producing nuclear weapons.
The leaders of the House Intelligence Committee yesterday asked for a similar review.
Since Iraq fell to US and British forces, search teams have found only limited evidence that directly supports the administration's claims. This includes two trailers that US analysts believe were mobile biological weapons production labs.
AP