Aust forces prepare for Iraq battle orders

The full contingent of Australian fighter jets and 600 military personnel will be in the United Arab Emirates within days, before joining the international force fighting Islamic State in Iraq.

The mission, which Prime Minister Tony Abbott has declined to call a war, is set to cost Australia at least $500 million a year and involve more than 30 countries.

"This is the world's fight. It is not just Iraq's fight," Mr Abbott said.

The prime minister, who may cut short his visit to Arnhem Land, was briefed in a teleconference on Tuesday by defence force chief Mark Binskin, Defence Minister David Johnston and new national security director-general Duncan Lewis.

Mr Abbott said the special forces and Super Hornet fighter jets would not be sent in without "very strict rules of engagement" and an "absolute plethora of legal documents" to cover operations in Iraq.

While Labor has given bipartisan support for the mission, West Australian backbencher Melissa Parke has voiced concerns that Australia's involvement in Iraq has escalated so quickly from a humanitarian mission to war.

The former United Nations lawyer said it would only increase the security threat to Australians.

Both Labor leader Bill Shorten and Mr Abbott said they understood there was some "anxiety" in the public and among politicians.

"The briefings, which I can't go into detail about, have convinced me that what happens in northern Iraq and Syria has repercussions for our safety in Australia," Mr Shorten said.

Mr Abbott warned the combat operations in Iraq would be "highly hazardous", but everything would be done to minimise the risks.

The government has not ruled out expanding the military role to Syria, but the prime minister said there was no intention to do so at this stage.

And in any case, it was a much more complex legal situation to operate in Syria, whose government is not recognised as legitimate by Canberra.

The Australian Defence Force's role in providing weapons to Kurdish Peshmerga forces in northern Iraq during the past two weeks has triggered questions over whether the guns will fall into the hands of terrorists.

The PKK, or Kurdistan Workers Party, which has been designated a terrorist group by Australia since December 2005, is working closely with the Peshmerga.

Mr Abbott said Australia had been given strong guarantees that weapons would be used only by the Peshmerga.

Meanwhile, after carrying out more than 160 air strikes in northern Iraq, US warplanes have begun their first strikes near Baghdad.

The future of the international mission will be discussed at UN meetings in New York next week, which will be attended by Mr Abbott.