Watch: Acting PM Winston Peters announces $2.3 billion to replace ageing Air Force fleet

The Government will spend $2.3 billion on four Boeing P-8A Poseidon maritime patrol aircraft to replace its ageing Air Force P-3 Orions.

The six P-3s have been in service in New Zealand since the 1960s and will reach the end of their operational life in 2025.

The $2.3b cost of the new P-8As, being purchased from the US Government, includes training systems, infrastructure and introduction into service, Defence Minister Ron Mark said.

They will be delivered and begin operation from 2023. The cost would be spread over financial years until 2026.

"The P-8A was the most cost-effective maritime patrol aircraft option available," Mark said.

Defence Minister Ron Mark says Boeing P-8A Orions were the only option for New Zealand's Air Force. Photo / Mark Mitchell

"The purchase ensures the Defence Force can continue to deliver the country's maritime surveillance, resource protection, humanitarian and disaster response around New Zealand and across the South Pacific," he said.

It also strengthened the Government's 'Pacific Reset' by providing a maritime patrol capability with the range and endurance needed to assist New Zealand's regional partners.

It also means New Zealand will have 'inter-operability' with other countries which use the P-8s, namely Australia, the UK and the US.

The Government is considering other ways to surveil our exclusive economic zone such as smaller manned aircraft, remotely piloted aircraft or satellites. That would free up the P-8As to fly more missions elsewhere.

Mark said the P-8As were the only option that delivered all the capabilities New Zealand required.

"The aircraft stacks up on its own merits."

Orion No 5 Squadron to move to Ohakea

As well as the decision on the new planes, Mark also announced that No.5 Squadron, which operates the Orions out of Whenuapai, would be moving to Ohakea.

That was for a number of reasons including that the runway at Whenuapai was short and weaponisation of the P-8s could not occur at Whenuapai because of the proximity to houses. Those weapons include anti-submarine weapons such as torpedoes.

"Ohakea lends itself better to the ability of the P-8s to be able to deploy, to be able to take off fully laden."

At a press conference this afternoon, Mark was asked whether the move would affect any decision to allow the Singapore Air Force to base a squadron of F15 fighter jets at Ohakea.

"It would be fair to assume that Ohakea can only take so much. The Singapore decision is a separate decision and we're looking at that quite separately. It will use up space, that is for certain," he said.

Acting Prime Minister Winston Peters said no decision had been made on whether to go ahead with Singapore's request.

Under the proposal up to 500 people extra would be stationed in or near Ohakea.

The Singapore Government last year undertook a feasibility study ahead of a proposal to go to both governments.

Mark said half of the $2.3b cost was for infrastructure, moving the Orion operation to Ohakea and training.

National's defence spokesperson Mark Mitchell said the previous government had put a lot of work into the procurement of the P-8As and he welcomed today's announcement.

"The procurement of the P8s sends a positive signal to our allies and partners, showing that we will remain a capable Defence Force, and are well equipped to play our role on the international stage, alongside providing support to regional security arrangements," he said in a statement.

On Phil Twyford's CAA rules breach

Peters said Transport Minister Phil Twyford had regained his responsibility for the Civil Aviation Authority following an announcement by the CAA today that he had been fined $500 for breaching CAA rules.

Twyford lost that responsibility when he reported himself to the CAA for using a mobile phone on a plane in breach of CAA rules in May.

On far-right speakers' ban from NZ

Peters said Canadian far-right writers Lauren Southern and Stefan Molyneux should be allowed to speak regardless of their views.