Luxon's office said he switched to an early morning scheduled flight out of Wellington, because of a last-minute problem with a New Zealand Defence Force Boeing 757 aircraft.

Luxon's party had to transfer to a flight on Air New Zealand, the airline he led for seven years as chief executive before switching to politics.

The prime minister was flying to Melbourne to attend meetings with leaders of Southeast Asian nations and the host country on the sidelines of an ASEAN-Australia summit.

During pre-flight checks, the crew of the military plane became aware of a technical fault with the nose landing gear system, a defence force spokesperson said. "The aim is to remedy the fault as soon as possible."

The Royal New Zealand Air Force has been asked to look at back-up options for when the prime minister returns on Wednesday, the spokesperson added.

The second of the two defence force Boeing 757 planes is unavailable in Christchurch for scheduled maintenance work.

This is not the first time there have been concerns about the reliability of defence force planes transporting New Zealand officials.

A back-up Boeing 757 was used for a trip to China last year in case of a breakdown when then-prime minister Chris Hipkins led a delegation to Beijing. As leader of the opposition at the time, Luxon had criticised the move.

ryj/djw/mtp

BOEING

Air New Zealand