Health Minister Andrew Little admits waiting times at the Emergency Department are getting longer but says health entities are doing all they can to make improvements.
The National Party said Emergency Department wait times are now the worst in at least a decade, with more than one in five people needing to wait for at least six hours for treatment.
Little said it is due to extra precautions being taken against Covid-19, staff absenteeism and vacancies at hospitals.
"We've invested very heavily in upgrading and building new buildings on our hospital estate.
"But we've still got more to do because the demand for health services is growing as our population ages and changes and we still have to continue the investment we've got."
In the last five years the government had added 5500 doctors and nurses to the public health system, made record investment in this year's Budget, and changed the health system, Little has said.
"We are spending more on our public health system than we have ever spent before. We have employed more additional people into our public health system than we have ever employed before.
"We see the data, we see the challenges, we work with the sector to make the improvements."
A recent survey of 900 doctors by the Women in Medicine Charitable Trust found that 93.5 percent said there was "definitely" a healthcare workforce crisis in New Zealand, and another 6 percent said there was probably a crisis.
Asked if there were currently any specific workforce issues in their workplace, 97 percent responded 'yes'.
Despite the current strains on the system, Little said people should visit hospital if they feel unwell and wait until they are assessed.