The Labour Opposition is walking back its openness to joining one wing of the AUKUS military pact.
Although it says it has not finalised its position, its associate foreign affairs spokesperson called it an "offensive warfighting alliance against China".
Australia aims to send officials to New Zealand soon to talk about pillar two of the defence deal it set up in 2021 with the US and UK.
Labour, when in government last year, said it was "willing to explore" participating in pillar two, which focuses on developing and sharing military technology.
Now, however, associate foreign affairs spokesperson Phil Twyford has weighed in saying, "If ... this government wants to join an offensive warfighting alliance against China, it needs to tell New Zealanders this.
"If there's a war in the South China Sea ... is it this government's intention to be dragged into that conflict on the side of the US?" Twyford told the House, at the time the defence and foreign affairs ministers were lined up to meet their Australian counterparts early this month.
Labour foreign affairs spokesperson David Parker told RNZ on Friday the Australian officials "will probably be trying to sell it" when they come here.
Labour would not be privy to those talks, but both the benefits and disadvantages must be looked at, over and against the loaded phrases about "not freeloading" that Minister Judith Collins deployed, Parker said.
"I'm not really interested in jingoistic phrases, I'm interested in serious consideration."
He stopped short of saying the new government should not be exploring pillar two.
"We're questioning its utility and whether it is wise."
The pillar two debate comes at a crunch time when a weakened and cash-strapped NZDF is working on a new Defence Capability Plan that will chart out billions of spending on priority technology for years to come.
Parker said Labour "remain unconvinced that pillar two offers us anything new that we don't already have".
Interoperable military tech could and was being achieved without it.
"We're not convinced we should be positioning China as a foe" and should not fall into a "trap taking a binary position that it's either the US or China", he said on Friday.
The defence minister seemed "a bit more gung-ho" than the foreign minister, Parker added.
"They haven't taken a final decision either, so we're not in a position that we need to take a final decision yet, but you can see that we're expressing our concerns that it's not necessarily in New Zealand's national interest."
AUKUS makes Pacific states nervous as its centrepiece is delivering nuclear-powered submarines to Australia, and could reorient security priorities away from the likes of combating climate change, towards a primary goal of aligning with the US.
Samoan Prime Minister Fiame Naomi Mata'afa speaking beside Foreign Minister Winston Peters on Friday, upon renewing a statement of partnership, said "we don't want the Pacific to be seen as an area that people will take licence in terms of nuclear arrangements".
Peters responded that New Zealand had demonstrated its anti-nuclear commitment alongside the Pacific for years. "We're not forgetting it now," he said.
China in response to the joint New Zealand-Australia ministers meeting, said it had serious concerns about AUKUS, which ran "counter to the letter and spirit of the international nuclear non-proliferation regime".
The AUKUS alliance rejects that; after the trans-Tasman meeting the "ministers acknowledged Australia's commitment to responsible nuclear stewardship", a joint statement said.
'New Zealand's interests lie in supporting peace, trade' - Twyford
Both Twyford and Parker emphasised Labour saw AUKUS as a military pact designed to contain China, New Zealand's largest trading partner.
"We are highly critical of their record on human rights and the treatment of minorities. But is that a reason to join a military pact against them?" Twyford said.
"New Zealand's interests lie in supporting peace, trade, international cooperation, the United Nations, not throwing our weight behind one superpower in its struggle against another."
Parker questioned the evidence for the joint trans-Tasman statement in which the ministers agreed AUKUS "made a positive contribution toward maintaining peace, security and prosperity in the Indo-Pacific".
Labour was pushing a more independent foreign policy now, under him and with the support of its caucus, he said.
Labour ministers last year said they were satisfied that pillar two was separate from the nuclear subs deal, and made the point to Beijing that New Zealand did not want to see the militarisation of the Pacific - "we're not part of the AUKUS arrangements", then foreign minister Nania Mahuta said in mid-2023.
However, papers released under the OIA show the government strove to "recalibrate" the key message to show New Zealand agreed with the rationale behind AUKUS, that there was a "deteriorating strategic environment" in the region.
Then prime minister Chris Hipkins said reinforcement to recalibration in April 2023: "New Zealand agrees with the AUKUS partners that the collective objective needs to be the delivery of peace and stability and preservation of an international rules-based system in our region."
Pillar two envisages partners rapidly developing and sharing the likes of military drones, artificial intelligence, quantum computing, cyber and undersea capabilities, and hypersonic weapons.