Prime Minister Tony Abbott won't put a time limit on Australia's commitment to the fight against Islamic State extremists, saying its deployment to the Middle East could last "many, many months".

Combat aircraft and special forces advisers will be sent to the United Arab Emirates as part of an international coalition after a specific request for support from the US government.

Asked if Australia had an exit strategy for the deployment of the 600 military personnel, Mr Abbott said: "I'm not going to put a time limit on it."

"It'll certainly be months rather than weeks, and quite possibly many, many months," he told the Nine Network.

The prime minister has said the deployment does not mean Australia is going to war in Iraq, with a decision yet to be taken to commit to combat operations against IS militants.

However, on Monday he defended the decision.

"This is a fundamentally humanitarian mission that is designed to protect people in Iraq from the murderous rage from this ISIL movement," he said.

Mr Abbott said the airborne component of Australia's commitment will leave for the Middle East by the end of the week, and some special forces could depart before then.

The prime minister, who is visiting Arnhem Land this week, said he'd be holding a number of teleconferences with officials in Canberra on Monday to manage the deployment.

He praised US President Barack Obama for building a broad and growing international coalition determined to defeat the Islamic State "death cult".

"President Obama has not been quick to reach for the gun here," he told the Seven Network.

"This is a very broad coalition and it's getting broader all the time. The ISIL movement is a threat not just to the people of northern Iraq, it's a threat to the entire Middle East, it's a threat that's reaching out to us."

Mr Abbott said it must be remembered that Australia had joined the effort to defeat the terrorist group at the invitation of the new Iraqi government.

Labor has given bipartisan support to the deployment, which will include up to eight Super Hornet combat aircraft and a contingent of special forces military advisers.

However, the Greens have condemned the move as "mission creep" and accused the prime minister of "blindly" following the US into Iraq.

With tens of Australians known to be fighting with terrorist groups in the Middle East, Mr Abbott said the decision was as much about domestic security as international security.

Australia's objective in any conflict would be the defeat of Islamic State in Iraq, he said.

"If the Iraqi government is once more reasonably capable of maintaining control over its own territory, maintaining internal security, that will be certainly a success," he said.

He also rejected suggestions that Middle Eastern countries were unwilling to get involved in Iraq.

"Jordan, Bahrain and the UAE are committed to military action and there a number of other Middle Eastern countries that are preparing to commit to military action," Mr Abbott said.

The prime minister said the commitment was not open-ended and Australia could withdraw after the Iraqi government and the Kurdish regional government regained "reasonable control".

"We're not trying to create a liberal pluralist democracy, we're not trying to create a shining city on the hill - what we're trying to do is to help the people of Iraq to help themselves, so the people based in their country will no longer threaten us," he told ABC television.

Australia's actions would be solely focused within Iraq's borders, Mr Abbott said, noting the US may target Islamic State militants in both Iraq and neighbouring Syria.

To do nothing would allow a bad situation to become "catastrophically worse", he said.

"The fact that there is no certainty of a happy outcome no matter what we do doesn't absolve us from the responsibility of doing what we can to protect our citizens, to secure our interests, to advance our values - and these values are fundamentally humanitarian," Mr Abbott said.

"We want to avoid the genocide, the potential genocide, that was unfolding in northern Iraq just a few weeks ago before the first US airstrikes, and the humanitarian airdrops by countries like Australia."