Labour leader Andrew Little told Australian Prime Minister Tony Abbott in their private meeting that Australia's air strikes against Isis in Iraq make sense because the Iraqis were saying air strikes were making a difference.
But he also told Mr Abbott that the plan for New Zealand and Australia to train Iraqi troops was an exercise in futility because it would be "propping up a corrupt and dysfunctional army".
Mr Little also told Mr Abbott that the description of sending New Zealand and Australian troops in a training mission "under some sort of Anzac tradition" was a sensitive issue in New Zealand and that New Zealanders did not necessarily see it in those terms.
Mr Little said dealing with Isis was more complex than "just knocking over the evil-doers".
"You can't negotiate with them but you have to cut off their funding supply, weapon supply, change the conditions in which they are recruiting young Muslims."