Iraq will ask Syria-bound Iranian planes passing through its airspace to land for random inspections after Washington said they could be ferrying arms to Damascus, the Iraqi foreign minister said in an interview.

US officials had raised their concerns over the past few days on the sidelines of United Nations General Assembly meetings in New York, Hoshiyar Zebari said.

"We have informed Mrs Clinton [US Secretary of State Hillary Clinton] and US officials the government plans to bring planes down and conduct random inspections," Mr Zebari said. He confirmed he was referring to Iranian planes.

Washington had already said it was asking Iraq about Iranian flights suspected of carrying arms to Syrian President Bashar al Assad, a staunch Iranian ally fighting an 18-month-old revolt against his rule.

Iraq has said it would never allow any arms to pass through its airspace to either side in the conflict.

The government of Iraqi Prime Minister Nuri al Maliki, a Shi'ite Muslim, is close to regional Shi'ite power Iran. Iran is one of the main allies of the Syrian president.