Air Chief Marshal Binskin admitted Islamic State forces had anti-aircraft weapons, but said Australia would take this into account in planning the mission, which will be flown by C-130 Hercules and C-17 Globemaster aircraft. He said the arms, which would supplied by "eastern bloc" countries, included rocket-propelled grenades, mortars and various calibres of ammunition. Asked how Australia would ensure the arms did not fall into the hands of the Kurdistan Workers Party or PKK, which has been fighting alongside the Peshmerga but is registered in Australia as a terrorist organisation, Air Chief Marshal Binskin said "the greater risk here is actually doing nothing, to be honest with you". Earlier on Sunday, independent MP Andrew Wilkie and the Greens expressed anger that the Abbott government committed Australia to weapon drops without consulting Parliament. Mr Abbott said Australia did not wish to become involved in the conflict, but it was important to do what it could to avert potential genocide.

"While we understandably shrink from reaching out to these conflicts, the truth is that these conflicts reach out to us. There are about 60 Australians that we know to be involved with terrorist groups in the Middle East. There is another 100 or so who are actively supporting those who are involved with these terrorist groups. The problem with significant numbers of Australians being involved with these terrorist groups is that they are radicalised, they are brutalised and they are accustomed to kill in the name of God. If it is right to kill in the name of God in Iraq, there is no reason to think that the same people won't do likewise, if they get the chance, elsewhere, including in Australia." Mr Abbott said described the situation in Iraq as "severe" and said it would remain so as long as Islamic State fighters retained control over large swathes of northern and western Iraq and parts of eastern Syria. Air Chief Marshal Binskin revealed that on Sunday morning, Sydney time, an Australian C-130 aircraft had participated in a humanitarian air drop to the besieged town of Amirli in north-eastern Iraq. The drop, which was assisted by US airstrikes, consisted of 15 pallets of food, water and hygiene packs, enough for 2600 people for a day. Australian C-17 aircraft would transport equipment and supplies to Erbil in the Kurdish part of Iraq in coming days.

Mr Abbott said Australia had not received any request from the US to take part in airstrikes, but would consider any such request. Asked to guarantee Australian combat troops would not be deployed, Mr Abbott refused to do so, adding "none of us want to get involved in another Middle Eastern war but it is important to do what reasonably can be done to avert potential genocide." The Prime Minister suggested Greens proposals to require parliamentary authority for military deployments were unworkable. "This idea that Australian forces cannot be deployed until the Parliament has met and approved the mission, I think, is novel to say the least when it comes to the deployment of military forces by Australia," Mr Abbott said. "There are all sorts of circumstances in which Australian forces could be deployed, must be deployed, where you couldn't have a parliamentary debate prior to their deployment." Loading

Asked whether Australia's support for anti-Islamic State fighters would increase the risk of terrorist activity in Australia, Mr Abbott pointed to comments made last week by spy chief David Irvine, who said there was no specific correlation between Australian government activity in the Middle East and domestic terrorist threats. "There is a certain type of terrorist organisation which hates us not because of what we do but because of who we are and how we live," Mr Abbott said. "Who we are and how we live, I hope, will never change."