The US State Department had questioned a previous deal between the Kurdish regional government and Texas-based Hunt Oil Company, noting that it might fall afoul of a hoped-for but long-delayed law on national oil revenue sharing.

"I don't know anything about those other deals," spokeswoman Dana Perino said, adding: "I believe that the central government still has to approve final contracts before they can be made final."

Perino also emphasized the need for passage of the hydrocarbon legislation, which would lay out an equitable distribution of oil monies among Iraq's warring sectarian groups, helping to defuse violence there.

"Oil revenues are being distributed throughout the country, but we believe the law needs to be passed," she said.

The regional government said in a statement posted on its website that it had approved four contracts for exploration and production, and had sanctioned two new refinery projects in the Kurdish autonomous region in northern Iraq.