"INZ does not have a list of 'high risk countries'," Carley said.
"INZ also does not decline visa applicants based solely on their country of origin or race."
He said the agency considers a number of risk factors when processing visas, and this may include risks associated with the country of citizenship of the applicant.
In the past six months, 66 per cent applications from Iraq were declined and about 60 per cent were from Afghanistan were also rejected. By contrast, just 5 per cent of Chinese and 10 per cent of Americans were turned down.
"INZ will apply a higher level of scrutiny to those applicants who have any risk factors present," Carley said.
"For security reasons and to uphold the maintenance of the law, we are unable to provide any specific information on risk factors that we apply higher scrutiny to."
Carley said there are requirements all temporary visitors to New Zealand must meet in order to be granted a visa.
These include having a genuine and valid passport, to be of good character and health, and to have a genuine reason for visiting NZ and sufficient funds to support their stay.
"The onus is on the visitor to satisfy INZ that they meet all the entry requirements at the time they travel to New Zealand," Carley added.
Half or more of the applications from 38 countries including Kuwait and Nigeria failed to satisfy INZ. However, foreign nationals from 25 countries received 100 per cent approvals.
The agency rejects about seven in 100 applications for visitor visas on average.