Prime Minister John Key isn't ruling out extending New Zealand's two-year Iraq deployment.
His comments come after Labour leader Andrew Little visited Kiwi troops at Camp Taji, at the invitation of Defence Minister Gerry Brownlee.
Speaking to The Nation at the weekend, Mr Little said there was "no way" New Zealand would be able to pull out in a year's time without undoing all their good work.
"It's not as easy as saying we've done some training, we're out of here, because there will be a vacuum left. And the question is, what do we need to do to avoid a repeat?"
Labour opposed the initial deployment and while Mr Little still does, "doing nothing is not an option" when it comes to defeating Islamic State (IS, also known as ISIS or ISIL).
Mr Key is wary of mission creep, telling Paul Henry this morning there was no intention to extend the mission beyond two years.
"If the test of whether we've done a good job is that we've completely trained the forces in Iraq that need training, then we'll be there forever," said Mr Key.
"That was one of the points I made on the way in -- I don't think New Zealand should be in this deployment forever. On the work that we're seeing at the moment, they're doing a great job. They've trained over 4000 people."
But he says "you can never say never".
"It comes down more to, should New Zealand play its part against ISIL? In my view, the answer to that is yes. The question is, how can we be the most effective? We thought that training troops in Iraq is the most effective and that's been my sort of thinking."
Labour opposed the deployment because previous efforts to train Iraqi forces have had limited success. A planned assault on Mosul later in the year will "be a test of whether the Iraqi Army has really transformed under the training that is being provided" he told the Nation.