BBC News, Washington
The US reconstruction programme in Iraq has been described as chaotic and badly managed, in an official report by the US special inspector general for Iraq.
The report said there was little oversight of Iraqi contractors
Stuart Bowen said tension and a lack of co-ordination between the Pentagon and the State Department led to disarray.
Mr Bowen presented his report to the Senate Homeland Security committee.
The panel's chairman, Joseph Liebermann, said billions of dollars had been wasted and the overall mission in Iraq had been undermined.
The US Defense Department never had a proper plan to manage the post-war reconstruction of Iraq, according to the man charged with investigating the efforts.
Stuart Bowen found numerous problems, from a lack of strategy to poor communication between the Pentagon and State department.
"Anyone who has spent appreciative time in the Iraq reconstructive effort understands the tension that exists between the two," he said.
Money flowed into projects, before training and staff were fully in place.
Only three contracting officers were initially sent to the capital, Baghdad, to oversee the spending of the reconstruction money.
There was little oversight for the Iraqi companies hired to do the work. The result was a lack of clearly defined authority and little financial accountability.
The report was not intended to lay blame with any one agency, but it recommended that government departments work together more closely in the future.
Unless things change, the same mistakes could be repeated.