Australia started conducting missions against IS forces in Iraq in October 2014 and extended that to include targets inside Syria in September.
The US has asked Australia and other coalition partners to increase their military contribution to the fight against Islamic State.
The defence minister, Senator Marise Payne, said Australia was already making a substantial contribution, though that was constantly under review.
“The Australian government is currently making a significant contribution and would welcome other like-minded countries making greater contributions where possible,” she said in a statement.
Australia’s contribution to the fight against IS in Iraq and Syria includes six F/A-18 Hornets, an E7-A Wedgetail airborne warning aircraft and a KC-30A tanker aircraft operating from the United Arab Emirates.
As well, 300 Australian troops, along with 100 New Zealanders, have been training Iraqi army units inside Iraq. A group of 80 Australian special forces have been advising the Iraq Counter-Terrorism Service.
Payne said the US secretary of defence, Ash Carter, and the chairman of the joint chiefs, General Joseph Dunford, had acknowledged that the US had approached coalition partners about their contributions to the fight against IS.
She said Australia welcomed recent announcements from several nations including the United Kingdom to increase their contribution.
The UK recently decided to begin launching air strikes against targets in Syria.