Major General Craig Orme said coalition air operations were having an impact on IS.
"We are in the first quarter, things are looking positive and the wind is with us," he said.
Australia's first air operation over Iraq occurred in August when a C-130 dropped food aid to members of the Iraqi Yezidi minority besieged on Mount Sinjar in the country's north.
Combat operations started on Sunday with Super Hornets conducting missions on all but one day. On two days four aircraft flew, on other days just two aircraft.
But bombs were dropped just once by one aircraft.
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Major General Orme said that the limited amount of bombing stemmed from the rules of engagement and the operating environment, with the Islamic State group showing they can adapt.
"They recognise the coalition's strengths and advantages and they are adapting in the way they operate, as any enemy at any time on any battlefield has either adapted or been destroyed," he said.
One consequence is that IS fighters no longer parade as openly as they once did.
"If they want to stay in one spot, we are very happy for them to do that. We will just bomb them," he said.
"When they do mass we will smack them and smack them hard."
Australia's next significant step will be deployment of a contingent of special forces to advise and assist Iraqi security forces on the ground.
The legal agreement for that to proceed is still being finalised.
Once that's in place, the special forces soldiers will move speedily from the Australian support base in the Persian Gulf to Iraq.
"We are working through both where we would be based and who we'd be supporting. There are options still on the table but we are fairly clear on the likely partners and how we will operate," Major General Orme said.
He said Australia's work was appreciated by partner nations.
"There is a real sense that Australia is making a significant contribution, that that contribution is highly valued, that that contribution is making a difference," he said.
