An announcement on whether Australian troops will work alongside New Zealanders in Iraq could be made as soon as tomorrow.
Australian Prime Minister Tony Abbott met with John Key on Saturday for their annual talks, at which the fight against Islamic State was at the top of the agenda.
Australia already has a 600-strong deployment in Iraq, undertaking air strikes as part of the US-led coalition and with 200 special forces personnel in "advise and assist" roles.
The Australian newspaper had details of the joint mission days before the New Zealand Prime Minister confirmed that 143 soldiers would head to Iraq in May to train Iraqi troops.
The other part of the mission that was leaked to media - the 300 Australians - has been slower to be revealed.
Australia's Foreign Minister, Julie Bishop, who was also in New Zealand, gave an icy response when she was asked what the holdup was.
"Well I'm sorry that the Prime Minister of Australia hasn't made announcements according to your expectations," she said.
Mr Abbott, however, was more forthcoming, saying an announcement could come as soon as tomorrow.
"We still have to finalise our processes in Australia and certainly it will be good to see Australia and New Zealand standing shoulder to shoulder in defence of our interests and our values."
Mr Abbott did not mince his words when talking up the threat of Islamic State, which he referred to as the Da'esh Death Cult.
"Our interests as well as our values are at stake here. The death cult has horrified the world, the way a new dark age has descended upon so much of Syria and northern Iraq.
"The crucifictions, the beheadings, the mass executions, the sexual slavery are horrific, horrific beyond words and yet we see them every day on our TV screens."
Labour Party leader Andrew Little also met with Mr Abbott over the weekend, and made his views on sending troops to Iraq very clear.
"I made the case that I thought the critical issue was propping up the Iraqi army, which was dysfunctional, poorly led and corrupt and I saw no value at all in contributing to that.
"He responded that dealing with an enemy like [Islamic State], something had to be done, it was that sort of argument and that he was convinced that something constructive could be done with the Iraqi army."