Ambassador Lukman Faily said that though Washington is the Iraqi government's first-choice arms supplier, "we have to choose whoever is available" because of the threat from the terrorist group of the Islamic State of Iraq and the Levant.

Iraq would be willing to buy arms from Iran, even though purchases from Tehran are prohibited under international sanctions, Faily told an audience at the Carnegie Endowment for International Peace.

"We will do that ... if we can't get cooperation elsewhere," he said.

The terrorist group's advance has sharpened a dispute between Washington and Baghdad over the US supply of arms to Iraq. The administration has been selling Iraq missiles, fighter jets and helicopters, but its supply has not been as large, or as fast-moving, as Iraq would like.

The United States is supplying Iraq with F-16 fighter jets and Apache helicopters, but they will not arrive until fall, and the Iraqi pilots will need to be trained.

On Sunday, Russia delivered 12 fighter jets to Baghdad, a move that illustrated Iraq's willingness to turn elsewhere.

President Obama has dispatched more than 750 US troops to Baghdad to help in the battle against insurgents, but he is moving cautiously.

Faily said Iraqis are convinced that the administration takes the militant threat seriously and that it intends to increase its involvement in stopping the group.

Iraq has bought $10 billion worth of arms from the United States, he said.

BA/BA