The way is now clear for New Zealand to deploy soldiers for a training mission in Iraq.
The Government has confirmed it has struck a deal with Iraq giving the troops adequate legal protections while serving there.
But Labour and New Zealand First said it was hard to know whether the protections were adequate because of a complete lack of transparency.
Defence Minister Gerry Brownlee said there had been an exchange of notes between the two countries that gave New Zealand the protection it required for its soldiers.
He said a deal had been struck that satisfied New Zealand's requirements.
"You can call it whatever you like. I mean, I think all that you ever get is an agreement between two countries about the circumstances under which the soldiers from your country undertake the activity, that they're designated to do, inside the other person's country."
Mr Brownlee said there would be some actions that would not be covered by the agreement.
"If someone does something deliberately, outside of the activity, then that would be a different matter and it always is a different matter."
Foreign Minister Murray McCully travelled to Iraq last week to finalise the deal.
Call for deployment deal details
Ministers would not reveal the details or the specific protections afforded to New Zealand soldiers.
But it is more likely to be an arrangement under which soldiers travel on official passports, rather than a full status of forces agreement.
Mr Brownlee said the details of the deal would not be made public because some of it related to activities New Zealand soldiers would be carrying out on the ground.
"Well why would you? It's an arrangement between two governments, it relates to the activities that our guys will be involved in and as you know there are security concerns around that."
Labour defence spokesperson Phil Goff said that was hardly reassuring.
"Well they say that they're having something that might provide equivalent protection but once again, without that information, how can we know?"
New Zealand First defence spokesperson Ron Mark said nothing short of a status of forces agreement should have been agreed to.
"Given the amount of time that they've been engaged in discussions behind the scenes, over the Iraq deploy, that we still don't have a status of forces agreement; that we have some sort of hodge-podge agreement and it appears that New Zealanders are not going to get to see it. That, we find absolutely unacceptable."
NZ troops already training in Australia
Mr Brownlee also confirmed New Zealand troops were already in Australia training for the deployment.
"You've got two militaries coming together. Now, we have good relations with the Australians but, where you've got to have interoperability on a mission like this, it pays to have a little bit of time as you go through the exercise of working out what that mission is going to look like."
Mr Brownlee said he was not sure of the exact number of New Zealand troops training in Australia but it was about 40 or 50.
The joint training mission will see 300 Australian troops joined by 143 New Zealanders deployed to an airbase north of Baghdad.
New Zealand troops were expected in Iraq in May to train local soldiers for warfare against Islamic State there.
It is estimated Islamic State has 31,000 fighters, of whom 18,000 are foreigners.