Two hundred elite special forces soldiers could be on the ground in Iraq within days after the Abbott government agreed to a US request to provide planes and 600 personnel to the region as part of a multinational strike force against Islamic terrorists rampaging through Iraq and Syria.

The decision follows US President Barack Obama's declaration last week to lead a coalition of nations to degrade and ultimately destroy the group that calls itself Islamic State, formerly known as ISIL.

It also came within hours of a third televised beheading of a Western man by the extremist group - British aid worker David Haines. ''This death cult is uniquely evil in that it does not simply do evil, it exults in evil,'' Mr Abbott said. ''This death cult has ambitions way beyond those of any previous terrorist group.''

Australia's special forces will initially be pre-positioned at Australia's military base at Al Minhad in the United Arab Emirates along with a contingent of another 400 air personnel, up to eight FA-18 Super Hornets, and two other aircraft.

These are an E-7A Wedgetail Early Warning and Control aircraft, and a KC-30A air-to-air refuelling aircraft, as well as ''associated support personnel required to operate and sustain'' these assets.

They will be in addition to C130 and C17 aircraft already supplied to airlift arms and supplies to Peshmerga fighters in Iraq's north.

Mr Abbott said the rise of Islamic State terrorism was a material threat to Australia which could not be ignored, warning the commitment was immediate and may last for ''many months''.

''This is not just an international security situation, but it is a domestic security situation,'' he said.

The final go-ahead for full participation in military operations now appears a formality.

''We could see the air elements departing in the next week or so. We could see the military elements departing sooner,'' Mr Abbott said from Darwin.

However, Mr Abbott said there were no plans for Australians to fight in Syria. He described the mission as essentially ''a humanitarian operation to protect millions of people in Iraq from the murderous rage of the ISIL movement''.

''Nevertheless we do have in contemplation the use of our

special forces in modest numbers to act as military advisers to the Iraqi army and to the Peshmerga,'' he said. ''The decision today was not to commit it to combat operations in Iraq although obviously that's something that we have in contemplation.''

The move came after special meetings of the National Security Committee of Cabinet and the full cabinet.

In the Northern Territory capital ahead of a week-long visit to indigenous communities in Arnhem Land, Mr Abbott confirmed the specific request had come from the US in the previous 24 hours. It came from Secretary of Defence Chuck Hagel to Australia's Minister for Defence David Johnston.

Since then, Mr Abbott had held talks with a number of other world leaders, including the newly installed Iraqi prime minister, Haider Al-Abadi, who made a direct request for military intervention to restore peace and security in his country.

Military and strategic specialist John Blaxland from the ANU College of Asia and the Pacific questioned how Australia could remain aloof from combat operations, or claim that there would not be ''boots on the ground''.

''We can play with semantics about what we mean by combat operations, but when you deploy Super Hornets, when you deploy the SAS, you don't deploy them to be 'Mr Nice-Guy'; they're essentially weapons of war.''

Western governments have dismissed the suggestion of a ground war in Iraq and Syria, but Mr Abbott did not comprehensively rule out an escalation of Australia's commitment. ''I don't anticipate the need for a stronger force but obviously these situations are things which are constantly kept under review,'' he said.

He listed the other countries that have agreed to participate as the UK, France, Canada, Jordan, Bahrain and the United Arab Emirates.

The decision received the unqualified support of the Labor opposition.

''Labor supports today's announcement of the deployment of an Australian military force - including RAAF assets and personnel - to the United Arab Emirates,'' Opposition Leader Bill Shorten said in a statement.

But the Labor leader stressed the need to avoid the tendency for mission creep which has seen ever increasing commitments in previous wars - including in Iraq.

However the Greens leader Christine Milne slammed the Australian commitment.

''Make no mistake, today Tony Abbott has sent us blindly following the US into yet another Iraq war,'' she said.