AIR New Zealand will "work constructively" with Boeing to secure its 787 Dreamliners, believing the US planemaker can deliver as it faces scrutiny into its manufacturing practices, reports Bloomberg.

The board of New Zealand's flag carrier is "very interested in what is happening" at Boeing, said chairwoman Therese Walsh, who plans to visit Boeing in the next year.

"We have to be really interested to make sure that we have the aircraft that we need and they operate in the way we wish them to," said Ms Walsh.

The airline is facing headwinds including intense competition on international routes and rising non-fuel costs. It's also grappling with Pratt & Whitney engine maintenance problems on its Airbus SE A321neo fleet.

New Boeing 787 Dreamliners, which will be powered by GE Aerospace engines and contain new business class seats and bunk beds in coach, won't arrive until at least mid-2025.

Air New Zealand also announced it will purchase 7,200 tonnes of sustainable aviation fuel from producer Neste Oyj's Singapore refinery.