The federal government has approved air combat operations in Iraq to fight Islamic State extremists.

The decision to send in Super Hornets as part of a US-led mission came after a meeting of the national security committee and cabinet in Canberra on Friday.

“Today cabinet has authorised Australian air strikes in Iraq at the request of the Iraqi government in support of the Iraqi government,” Prime Minister Tony Abbott said.

“Also, subject to final legal documentation, cabinet has authorised the deployment of Australian special forces into Iraq to advise and assist Iraqi forces.”

Six Super Hornets, a Wedgetail surveillance aircraft, a KC-30 refueller and a special forces contingent have been pre-deployed to the United Arab Emirates.

Australia ended its military commitment to Iraq in July 2009, after six years of war involving more than 20,000 personnel.

Abbott warned the mission would be “quite lengthy” and would be months rather than weeks.

“I want to assure the Australian people this will be as long as it needs to be, and as short as it possibly can be,” he said.

Only Iraq can defeat IS, but Iraq shouldn’t and won’t be alone, Abbott said.

He warned it would be a dangerous mission.

But he’s confident the Defence Force has all possible measures to minimise risk in place.

“It is a combat deployment, but it is an essentially humanitarian mission to protect the people of Iraq and ultimately the people of Australia from the murderous rage of the ISIL death cult,” Abbott said.

“It is absolutely in Australia’s national interests that this mission go ahead.”

Abbott said Opposition Leader Bill Shorten had given his full support.

Defence Minister David Johnston said the Iraqi government was “gratefully welcoming” of Australia’s role.

“The skill, commitment and professionalism of our uniform personnel is simply first class,” he said.

“They will do a very good job for us.”

Defence Force chief Mark Binskin said the air task group and commando unit were “potent”.

“The team is well trained, they’re well equipped, they’re well prepared,” Air Chief Marshal Binskin said.

“The air traffic group’s been flying supporting missions and some training missions over Iraq for the last couple of days and we’re ready to get on with the job.”

The Prime Minister again refused to rule out potential involvement in Syria and cautioned against trying to predict future missions.

“Let’s focus on what’s being done today rather than speculate on what might be done in months or years to come,” he said.

Success would be evident when the Iraqi government was restoring control over its own cities and towns and when IS was in retreat.

“If we could degrade them to the point where they no longer existed that would be obviously the best possible result.”

But Abbott said Australia was not at war.

“I know that you’d love to have that headline, but it’s not strictly accurate,” he told reporters.

“Yes, we are engaged in combat operations. But these are combat operations against an insurgency in support of the legitimate government of Iraq.

“We’re not trying to build liberal pluralism in Iraq, we’re not trying to create a shining city on a hill.”