Consideration would also be given to any troops who said they didn't want to go to Iraq on ethical grounds.
"The same consideration would be given as that applied to any other issue that may impact on their ability to deploy," the spokesman said.
"Personnel may at times indicate personal or other circumstances that could impact on their ability to deploy. As has been the case with most employers, NZDF has become increasingly aware of the effect of individual personal circumstances on the performance and overall wellbeing of its people."
Former Chief of Army Major General Lou Gardiner said troops had always been able to withdraw from a deployment - but only those who had legitimate reasons.
"Otherwise your mates would always see you as a person who opted out," he said. "It's human nature."
The Defence Force said it did not frown upon staff who sought permission not to go on a foreign deployment.
"But as a serving member of the military it is reasonable to expect to be deployed at some time," the spokesman said.
He added that as a "good employer", the Defence Force had to be able to respond to individual circumstances and "accommodate them where possible and appropriate".
The policy had been in place "in one form or another to all conflicts which New Zealand forces have deployed".
"We recognise that military personnel are people who have lives and families and individual circumstances that may mean they are less appropriate for a particular deployment," the spokesman said.
Victoria University's Centre for Strategic Studies regional security fellow Paul Sinclair said he would be very surprised if there were any opt-outs, unless there were exceptional circumstances.
"Most personnel - a very large majority - join to have the experience of serving and working overseas and there haven't been many opportunities in the last few years since we came out of Afghanistan," said Sinclair who headed the Defence Force's International Relations Branch from 2000-2012.
"Where there would be a potential complication was if there was a shortage of particular skills and they couldn't afford to have gaps."
The Defence Force is yet to confirm the final make-up of the initial deployment to Iraq, but the spokesman confirmed it would include female troops.
Planning was also under way for a support network for families of troops involved in the deployment.
Rise of an enemy,
Insight p30-31