Reconstruction efforts in Iraq worth $20bn (£11.5bn) are being hampered by inefficiency and insurgent attacks, a US audit has concluded.
Electricity supplies are still irregular in Baghdad
The latest report by the inspector general for Iraq's reconstruction says the US and Iraq both need to increase security around oil and gas facilities.
The findings were published three years after President Bush declared an end to "major combat operations" in Iraq.
Mr Bush said Iraq had finally "turned a corner", but faced more tough times.
The new report is the latest in a regular series of updates to Congress.
Some 67% of the $21bn cash has been spent, with only $2bn still to be allocated to specific projects, the report's author said.
Last Friday a congressional report suggested that the total costs of ongoing campaigns in Afghanistan and Iraq could reach $811bn (£445bn).
In his quarterly report to Congress, Special Inspector General Stuart Bowen said there were encouraging trends in the reconstruction of Iraq.
"Despite certain setbacks, chiefly caused by security problems, the overall picture conveys a sense of substantial progress in the relief, recovery and reconstruction of Iraq," Mr Bowen said.
US FUNDS IN IRAQ
Security and justice 34%
Democracy, education 12%
Oil and gas 9%
Source: Special Inspector General for Iraq Reconstruction
But he found "significant shortcomings" within Task Force Shield, a programme instituted in 2004 by the now-defunct Coalition Provisional Authority to protect Iraq's oil and gas installations from sabotage.
"Insurgent activity continues to impede ongoing reconstruction projects and interrupt their transition to Iraqi control," Mr Bowen concluded.
Iraq's oil industry is currently producing 2.18 million barrels per day, below pre-war levels and the current official oil ministry target of 2.3 million.
Success and failure
Elsewhere, efforts to improve health care facilities were judged unsatisfactory by visiting auditors.
In his report, Mr Bowen revealed that a programme to build 150 primary health care centres across Iraq had been scaled back.
Just 20 centres are now due to be completed, although most of the money allocated to the programme has been spent.
But the report did detail successes in other aspects of reconstruction: police, fire and the judicial system were being rebuilt, with 80% of transportation and 90% of education projects also complete.