Retired Admiral David Nash, the top official overseeing the $18.6 billion contracts, said he did not expect major delays in future.
The US opened up bidding last week for the first string of lucrative new contracts, worth $5 billion, after more than a month's delay.
"Hopefully we'll have contractors on the ground at the latest in late March, early April," Nash, who heads the Pentagon-run Programme Management Office, said.
"The way the contracts are set we are encouraging them to mobilize very quickly because we need to get to work very quickly," he said.
"Hopefully we'll have contractors on the ground at the latest in late March, early April"
Admiral David Nash
Programme Management Office
The bids for prime reconstruction contracts covering electricity, water, buildings, security and justice and transportation and communication are due in February and Nash said he expected them to be awarded by early March.
The first round of Iraq contracts were heavily criticised with US lawmakers alleging favouritism. The most controversial was the contracts awarded to Halliburton, an oil services company once run by US Vice-President Dick Cheney.
Nash however said there would be several layers of monitoring to ensure fair competition and discourage corruption.
"We are going to have lots of oversight," he said.
It was not clear how much of the reconstruction work would go to Iraqi companies, who have complained of being ignored.
While Iraqi firms have been awarded many sub-contracts, these have tended to be on smaller projects.