Iraq has requested US air power to try to reverse rapid territorial gains by Sunni Muslim insurgents.
Iraq Foreign Minister Hoshyar Zebari told reporters about the request after a meeting of Arab foreign ministers in Jeddah in Saudi Arabia.
He said Iraq had asked for air strikes "to break the morale" of the Islamic State of Iraq and the Levant (Isis) which has captured cities and towns in the north in a lightning advance over the past week.
"Iraq has asked officially help from the United States of America, according to the strategic deal between Iraq and the US to help in directing air strikes and help on some vital targets of these groups to break their morale and to help the security forces in pushing away the danger of these groups and to start defeating them."