Reports from Iraq suggest New Zealand-trained Iraqi troops are about to launch a major offensive against Islamic State to try to reclaim the city of Mosul.
Prime Minister John Key said he had not been briefed on any mission, but said the reports validated the government's decision to send trainers to Iraq.
He said New Zealand trainers had helped upgrade the skill and capability of the Iraqi forces and that had helped them take the city of Ramadi.
"Mosul is obviously the next big objective so it makes sense that they will be planning to do that and they will certainly be taking confidence from the way they carried out the regaining of Ramadi.
"I think it actually vindicates what I was saying last year, when I was putting up the case to New Zealanders that I thought that we should be sending our troops to train the Iraqi forces."
The decision to send New Zealand trainers was the right one, Mr Key said.
"Firstly, we have seen over Christmas the sorts of terror threats in the region that New Zealanders travel to, like Jakarta, secondly we have seen really good work happening which has upskilled people and thirdly, I think, you are seeing widespread public support."
Labour's defence spokesperson Phil Goff said there was no doubt that retaking Mosul would be a major step in the Iraqi Government's fight against Islamic State.
But Mr Goff said it was too early to speculate on the result and the Iraqi forces faced a lot of challenges.
"It is not simply a matter of training, provided by Australia and New Zealand...The big problem with the Iraqi army in the past has been incompetent leadership and deeply entrenched corruption."
New Zealand trainers might not be taking an active part in the mission but there was no room for complacency about their safety, he said.
New Zealand First's Ron Mark said the government should be providing more information about New Zealand's involvement in Iraq and its future intentions.
"Most of us are expecting that the government will come to Parliament and come to the people of New Zealand and justify an expansion of the operation...and deployment of more troops and so, with that in mind, yes we do need some truth. We need some truth and honesty and transparency."
Defence Minister Gerry Brownlee could not be reached for comment.