Iraqi forces holding own, says Aust chief

Iraqi troops are holding their own against Islamic state militants and Baghdad is not in danger of falling, the acting head of Australia's defence force says.

Vice Admiral Ray Griggs has rejected suggestions Iraqi troops aren't willing to fight the extremists, saying they have been involved in heavy fighting across the country.

He's also disputed predictions that Baghdad could soon fall.

"People have been saying that Baghdad could fall in a week or three months," he told ABC Radio.

"My understanding is that it is relatively stable ... (and) the Iraqi security forces are holding their own."

Prime Minister Tony Abbott has said Australian special forces could be deployed to Iraq within days, where they will provide an advisory role to local forces.

Vice Admiral Griggs played down claims that Iraqi forces weren't willing to fight IS, who are advancing on the capital.

Iraqi security forces have been involved in "very heavy fighting" in the west of the country, while Peshmerga forces had been resisting IS in the Kurdish north, he said.

"I don't agree that you've got a force that doesn't want to fight - they are engaged in heavy combat in a number of areas," he said.

"The airstrikes are playing a crucial role in supporting the Iraqi security forces and the Peshmerga in being able to do their jobs."