A week after Foreign Minister Nanaia Mahuta visited top Chinese diplomats, who raised concerns at the military tie-up between Australia, the United Kingdom and United States, Defence Minister Andrew Little says scoping talks are under way.

"We have been offered the opportunity to talk about whether we could or wish to participate in that pillar two aspect of it. I've indicated we will be willing to explore it," Mr Little said in Wellington on Tuesday.

AUKUS was first mooted as a deal between Australia, the UK and US that would see Australia receive nuclear-powered submarines to bolster its defence.

A second pillar to the tripartite deal covers the sharing of advanced military technologies, including quantum computing and artificial intelligence.

NZ has not been offered the chance to join pillar one, nor would it accept, due to its firmly held anti-nuclear position.

Mr Little said any AUKUS membership "could not compromise our legal obligations and our moral commitment to nuclear-free".

"(AUKUS membership) would be about the kind of technology ... needed to protect defence personnel," he said.

"Usually domain awareness, so surveillance technology, and radio technology that allows us to do that."

The talks come after Mr Little met with top US security official Kurt Campbell earlier this month.

AUKUS has plenty of critics across the Tasman Sea, including former prime minister Helen Clark who said it was not in NZ's interests to be associated with the deal.

During her visit to Beijing last week, Ms Mahuta said Chinese officials made clear their concerns with her.

"They acknowledged that our position on the matter. We're not a part of those arrangements," Ms Mahuta said, which suggests it was important to clarify New Zealand's non-involvement.

NZ has other concerns with AUKUS, including it may jeopardise the Treaty of Rarotonga which designates large swathes of the Pacific free of nuclear weapons.

"Our concern is not to see the militarisation of the Pacific, that the Treaty of Rarotonga be upheld, and that's the basis upon which our assurances from Australia have been gained in relation to those arrangements," Ms Mahuta said.

China is vociferously against AUKUS, with foreign ministry spokesman Wang Wenbin outlining China's "severe concern and firm opposition".

It is not clear whether China holds the same concerns of pillar two of the AUKUS deal.

In an interview with AAP last week, opposition foreign affairs spokesman Gerry Brownlee raised his own concerns of AUKUS, arguing it may make Anzac forces interoperable.

On Tuesday, he walked back his comments, saying he was "certainly not" trying to criticise the deal.

"Australia will make decisions for Australia," Mr Brownlee said.

Mr Little said foreign or local voices against the deal would not be a factor in potential membership.

"We as a country and the leaders of the day have to make an assessment about our long-term best interests and what is a rapidly changing world and a rapidly changing region," he said.

Ms Mahuta's trip to China was the first by a New Zealand minister since 2018.

While in Beijing she met with Foreign Affairs Minister Qin Gang and China's top diplomat, Central Foreign Affairs Commission director Wang Yi.

Ms Mahuta described the trip as positive, in keeping with "the nature of the bilateral relationship".

"New Zealand has taken a very consistent, predictable and respectful approach to raising issues with China. They registered with us that that is a positive way of working," she said.

Ms Mahuta said she raised concerns around human rights breaches in China, and also speculation it would supply lethal weapons to Russia for its invasion of Ukraine.

"We had asked China to use its influence with Russia to cease war," she said.

Ms Mahuta's visit is expected to precede an official visit by Prime Minister Chris Hipkins within months.

Australian Associated Press