According to Sky News, the airline’s chief Greg Foran said in an email to customers that the move was "a step towards opening back up to the world".
"It looks like proof of vaccination and pre-departure testing are going to be a part of flying for a while yet," he added.
"Increasingly, the places Kiwis like to fly to will be closed to unvaccinated visitors, and we’re working on ways to streamline the travel process for you."
The new mandate will apply to travellers aged 18 and over departing or arriving in New Zealand. Allowances would be made for passengers who cannot be vaccinated for medical reasons.
The move comes after Qantas chief executive Alan Joyce told Australian television that the airline was also likely to require all passengers to be vaccinated against the virus.