A U.S. State Department spokesman, Tom Casey said the U.S. and Iraq are forming a joint commission to review government-affiliated security detail operations.
Both the U.S. and Iraq are investigating a deadly shooting by a U.S. security firm in Baghdad on Sunday.
Iraqi Prime Minister Nouri al-Maliki says the activities of the firm, Blackwater USA, have been stopped while the government investigates.
Mr. Maliki said Wednesday his country will not tolerate the killing of its citizens in "cold blood."
Iraqi officials say at least 11 people were killed when Blackwater personnel fired in a busy area in Baghdad. The North Carolina-based firm says the convoy its employees were protecting came under attack and that its personnel acted "lawfully and appropriately."
Blackwater provides security for U.S. government civilian employees in Iraq.
The United States has barred U.S. diplomats and other civilian officials from traveling by land outside Baghdad's heavily fortified Green Zone.