Air New Zealand has announced that it will require passengers to be vaccinated on international flights from February.
The airline's chief executive Greg Foran said in an email to customers that the move was "a step towards opening back up to the world".
He added: "It looks like proof of vaccination and pre-departure testing are going to be a part of flying for a while yet.
"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 rule will affect international travellers aged 18 and over departing or arriving in New Zealand.
Mr Foran said allowances would be made for passengers who cannot be vaccinated for medical reasons.
When asked by TVNZ if the measure would be brought in for domestic travel - where the airline has a monopoly in much of the country - he replied: "Let's see what happens".
It follows a similar move from Australia-based Qantas.
Qantas chief executive Alan Joyce said as early as late last year that the airline would only take vaccinated passengers when international travel resumes.
Australia announced last week that an 18-month ban on its citizens travelling abroad would be lifted next month.
Many of the world's airlines and governments require proof of a negative COVID-19 test before a person can board a flight, but very few have said they will require vaccination from passengers.
A number of airlines have introduced compulsory COVID-19 vaccination for employees, however.
According to figures from New Zealand's Ministry of Health, 46% of the eligible population have been fully-vaccinated but this translates to just 39% of the total population.
Air New Zealand announced in October 2019 that it would axe its only UK service - which had run between Los Angeles and London - in September 2020.
The arrival of the coronavirus pandemic, however, hastened the move and the airline flew from Heathrow for the last time in March 2020.
Its remaining international routes run between New Zealand and Australia, the Pacific islands, Asia, and North America.