New Zealand First's Ron Mark says he was shocked by the response he got from the Army to an Official Information Act request over how Iraqi troops trained by them are performing.

Mark, a former solider, said they don't do any follow up once the troops leave their training at Taji.

He's astonished we're spending $65 million a year training Iraqis to fight ISIS and yet we know nothing about what happens to them after they leave camp.

"We're told that they're going into action, we're told that apparently they've been effective, but we have no measuring stick and so the next contingent that goes through training at Taji should be getting the benefit of any adjustments done to the training regime based on the feedback and the performance assessment in the field."

Prime Minister and the Defence Minister have both been to Taji and have declared the work we're doing there is top notch, but Mark is skeptical of their claims.

"The facts are that they don't know, because there is no evaluation as to how effective the training has been once those soldiers have left Taji and gone into action."

New Zealand has deployed 143 Defence Force personnel to support a two-year training mission in Camp Taji, just north of Baghdad, in tandem with the Australian Defence Force.