CANBERRA, Australia -- Australia was sending two unarmed air force planes to support U.S.-led coalition combat operations against the Islamic State movement in Iraq, but would not yet launch its own airstrikes, the prime minister said Wednesday.

An E-7A Wedgetail early warning and control aircraft and a KC-30A refuelling plane will join operations from the al-Minhad Air Base outside Dubai, Prime Minister Tony Abbott told Parliament.

Cabinet ministers were awaiting final clearances from the Iraqi government before deciding on combat missions, Abbott said.

The Australian government can commit troops to war without asking the Parliament for permission.

"We have not yet made a final decision to commit our forces to combat, but Australian aircraft from today will start flying over Iraq in support of allied operations," Abbott said.

Abbott reiterated his support for the Iraqi government, and said Australia could make a difference in the fight against Islamic State fighters who control swathes of Iraq and Syria.

"Our objective is to support governments that neither commit genocide against their own people, nor permit terrorism against ours," he said.

Australia's commitment to combat has been widely anticipated since six F/A-18F Super Hornet jet fighters, along with the two support aircraft, were deployed to the United Arab Emirates two weeks ago in response to a formal request from the United States for specific contributions to the international coalition.

The government says the number of Super Hornets in the Middle East could soon be increased to eight.

The Australian deployment also includes a 200-strong ground force, including special forces, to advise security forces inside Iraq, plus 400 air force personnel.

Abbott has restricted Australian combat operations to Iraq and has ruled out Australian troops fighting on the ground.

He said the beheadings, crucifixions, mass executions, ethnic cleansing and sexual slavery already witnessed in northern Iraq and Syria were only the beginning if the Islamic State movement had its way.

"This apocalyptic death cult has declared war on the world and it must be resisted at home and abroad," he said.

Australian is among dozens of countries from Europe, Middle East and including Canada that have signed up to the U.S.-led coalition fighting the Islamic State movement in Iraq and Syria. Contributions vary and include military assistance and humanitarian aid as well as carrying out airstrikes.