Mr Brownlee said through a spokesman that the Defence Force had begun "some training and preparation on a contingency basis".
"This is required to ensure there is a suitable time to build an effective level of capability should the Government decide to deploy.
"Training will focus on areas that cannot be developed to a sufficient level of competence in a short timeframe, such as language and cultural training, and risk mitigation measures. The units involved are those whose capabilities are most likely to be called upon in that environment, should an NZDF deployment take place."
Mr Key yesterday said any deployment decision would come once a scoping team of four sent to Iraq had provided advice. That would probably be some time late next month or early February.
Commenting on Australian reports yesterday of talks up to the prime ministerial level about a joint force to serve in Iraq, a century after the first Anzac force was created, Mr Key said that was "fundamentally wrong because it talks about a combat force".
"There will be no Anzac combat force but what is possible is that New Zealand joins up with Australia as part of a training capability. It's not impossible that they could be badged as an Anzac unit. That is possible but we're a long way away from agreeing that."
He said neither Australia nor New Zealand had made a formal commitment to a training role and New Zealand had yet to identify a suitable base for such a force.
If a joint training force bearing the Anzac badge was formed, the badge would be "fundamentally just symbolic". A joint force could present problems as "Australia could have a different response to Isis from us", Mr Key said.
"We've already seen them deploy their SAS. We're not doing that unless we do it as part of our protection, for instance."
He would not want to commit to a joint force that had a mandate that went beyond New Zealand's position on Iraq or that compromised New Zealand's ability to deploy or bring back personnel independently.
Mr Key said he had discussed the matter with Australian Prime Minister Tony Abbott.
What's being considered?
A joint Australia / New Zealand military force to conduct training for the Iraqi Army which could be "badged" as an Anzac force, i.e. wearing insignia which refers to the Anzac forces that fought together at Gallipoli.
Why badge them as Anzacs?
As a symbolic gesture to mark the centenary of the Gallipoli landings.
How big could this be?
Australia is reportedly considering a deployment of up to 400 personnel while New Zealand is considering sending 40-100.
Who might be going?
The Herald understands that along with trainers, New Zealand could send troops to protect those trainers and their base. The protection force could be SAS or regular forces such as infantry. Engineers could also go in order to set up the base.
What are the risks?
While away from combat zones there is always the risk of a direct attack on a base set up in Iraq or a "green on blue" attack where Iraqi personnel turn on their trainers. A joint force could also tie New Zealand to Australia and its harder line on Islamic State.
