NZ must consider cost of joining Pacific defence alliance

A geopolitics expert says before New Zealand asks to join a defence alliance with Australia and Fiji, it must first consider if it can afford to.

The government announced on Thursday that it was exploring membership of the Ocean of Peace Alliance, which was signed in Fiji on Monday.

Associate Professor Anna Powles, from Massey University's Centre of Defence and Security, said New Zealand needs to have the capability and resources to defend alliance partners if it ever comes to it.

"Australia is a much larger economy, larger military, et cetera," Powles said. "The key question here for New Zealand will be how it's going to contribute to the alliance both materially and in other ways, and that costs money."

She said one benefit of joining the alliance would be to ensure New Zealand remains integrated in Pacific regional security, particularly if the alliance's membership increased.

Pacific nations with militaries like Papua New Guinea and Tonga could join the alliance if its signatories agreed.

"If New Zealand does join, it would certainly help to shape a future direction of this alliance into becoming a potentially expandable Pacific-centred security alliance, rather than simply another bilateral defence arrangement.

"It would also give New Zealand a voice in deciding the shape of that future alliance."

On Thursday, Prime Minister Christopher Luxon said he disagreed with the claim by China's embassy in Fiji that the countries were engaging in "geopolitical rivalry".

Powles said there would likely be "diplomatic pushback" from China, and that it would see the alliance as a "form of strategic entitlement".

But she said New Zealand's membership would strengthen its relationships with Australia and Fiji at a time of heightened insecurity within the Pacific and around the world.