Chris Hipkins is refusing to budge on New Zealand's nuclear-free status and says there are still no plans for Aotearoa to join a non-nuclear arm of a US-led defence alliance.
The Prime Minister appeared on AM on Tuesday, having just returned from a trip to Papua New Guinea to meet with US Secretary of State Antony Blinken and Pacific leaders.
"I was pretty clear [with Blinken]; New Zealand's nuclear-free position is long-standing and it's not going to change," he told host Ryan Bridge.
Hipkins noted that position would prevent New Zealand from "ever" being directly involved in a defence alliance between Australia, the UK and the US - known as AUKUS.
"The US is still committed to a security relationship with New Zealand regardless of our nuclear-free status - I think that's a good thing."
Hipkins would not be drawn on even considering the possibility of allowing US nuclear submarines into New Zealand waters.
"We don't allow those in New Zealand waters and that's not going to change," he said. "Many other Pacific nations have similar concerns."
Bridge asked Hipkins what New Zealand's specific concerns were.
The Prime Minister said New Zealand was "concerned about nuclear energy… because of the environmental impact of it, and the potential for environmental disaster".
As for New Zealand joining a second, nuclear-free tier of AUKUS, Hipkins reiterated it remained unclear how that would work.
It comes after Defence Minister Andrew Little earlier this year confirmed Washington had raised the possibility of New Zealand becoming a non-nuclear partner of the alliance.
"We won't ever be involved in pillar 1," Hipkins said. "At this point, pillar 2 of the AUKUS arrangement - we're not clear what that might look like but we've got existing security arrangements that we're quite committed to."