Air New Zealand has signed its largest deal yet for sustainable aviation fuel.

The airline purchased 9 million litres of fuel from provider Neste, which is expected to reduce carbon emissions up to 80 percent compared to fossil jet fuel.

Chief Sustainability Officer Kiri Hannifin supports mandating other airlines follow suit to decarbonise.

"All of aviation is required to decarbonise, so we all have to do it, and there's only very limited ways to do it.

LISTEN ABOVE