Prime Minister John Key has informed Australia and Iraq of the Government's plans for military deployment to Iraq and will set out the details in Parliament this afternoon.
Mr Key has all but confirmed New Zealand will be sending troops to Iraq to help train local forces.
There was likely to be an intelligence gathering role, possibly to help direct air strikes against Islamic State fighters.
The prime minister said in any deployment New Zealand troops would have the flexibility to protect themselves, but not to come to the aid of Iraqis under fire.
"If we announce that we're sending people to train Iraqi forces we're just doing that, training Iraqi forces," Mr Key says.
"To stand up to ISIL [Islamic State] to combat ISIL but it's not New Zealand at war with ISIL, it would be New Zealand providing services to assist others."
Mr Key said New Zealand could also help with intelligence gathering - possibly to assist with airstrikes.
"Intelligence gathering has been a function that we have done in the past in lots of locations. We've certainly done that in places like Afghanistan that's been well and truly documented.
"It could be [for] airstrike assists, it could be for a variety of different reasons."
Opposition opposes deployment
The Government has the support of ACT only; all other political parties in Parliament oppose sending New Zealanders to Iraq.
Labour Party defence spokesperson Phil Goff said it seemed the public had been the last to hear Mr Key's decision.
"It's abundantly apparent that he's told leaders in Australia, in the United Kingdom and in the United States that we will be sending 100 trainers to be ground troops in Iraq.
"Why did he tell leaders of other countries that before he took New Zealanders into his confidence?"
Green Party co-leader Russel Norman said the West waging wars in the Middle East created the conditions that gave rise to Islamic State in the first place.
"We're basically putting people in harm's way; some of our troops will be putting their lives in danger and for what?
"For adding to the problem of Western intervention in the Middle East, which in the past has solved nothing and in fact has made it worse," Dr Norman said.
New Zealand First leader Winston Peters said the Government decided to go to war long ago.
"No matter what your political perspective is this is an extended exercise in deception, this decision was made a long time ago.
"All you're seeing now is the choreography of propaganda to try and prop it up," Mr Peters said.
United Future leader Peter Dunne was disturbed to hear the Prime Minister say there was also a role for intelligence operatives to play.
"It confirms my fears that this is an escalating situation and that the 100 people that we're sending are going to have a much broader role than we might first have imagined," Mr Dunne said.
It's likely the New Zealand troops will team up with their Australian counterparts in a joint training force.
An announcement about that is expected out of Canberra today.
The Prime Minister has also confirmed he will host a visit from Australian counterpart Tony Abbott in Auckland at the end of the week.