Prime Minister Jacinda Ardern says news another managed isolation and quarantine system worker has been infected with Covid-19 is not a failure.
The Ministry of Health announced on Friday a Defence Force worker had picked up the virus, and another case was announced on Sunday.
It comes as epidemiologists are urging a rethink on how the government handles workers testing positive for Covid-19.
"We've had a nurse infected, a maintenance worker, a port worker. These are system failures because we should be stopping all cases at the border," public health professor Nick Wilson told Morning Report last week.
Wilson would like to see isolation and quarantine moved out of hotels and into a purpose built facility outside a major economic centre and arrivals from high-risk countries limited.
Ardern said she wouldn't agree with calling the workers picking up the disease a failure.
"The reason we have the quarantine system, the contact tracing system, the Covid tracer app, all of that is an acknowledgment that we are trying to keep a virus, out of our country at a time when it is surging."
She said both workers involved in the recent cases had been wearing PPE at the time and an investigation is ongoing into how they managed to get the disease.
But the government also has to be prepared for instances like this.
"It is extraordinarily difficult to, in every case, have a foolproof error-free response to a virus."
Ardern said she was not interested in limiting any arrivals to New Zealand.
"We would be telling New Zealanders, as citizens and permanent residents, that if they came from certain parts of the world they could not come home. That's not an option for us, you cannot bar citizens from returning to their own country."
