The agency recommended that government contracting officials demand fixes within 45 days and seek more detailed information during negotiations with Halliburton, which has contracts worth as much as $18.2 billion in Iraq to feed and house troops and restore the country's oil infrastructure.

Halliburton faces numerous investigations, including an FBI inquiry into whether two of its employees received up to $6.3 million in kickbacks and whether the company improperly billed for $186 million in meals never served at dining halls in Iraq.

A federal grand jury in Texas has launched a criminal inquiry into whether Halliburton violated U.S. sanctions against doing business in Iran by working through a foreign-owned subsidiary registered in the Cayman Islands.