Growing friction with China and how to reopen borders after the pandemic will likely be among the topics discussed by Jacinda Ardern and Scott Morrison in their first face-to-face meeting since the coronavirus outbreak prompted both countries to close their borders.
The Australian prime minister arrived in the tourist resort of Queenstown for an overnight visit on Sunday.
He greeted his New Zealand counterpart with a traditional Maori hongi.
Mr Morrison's arrival came hours after the New Zealand government chose to support Canberra in its dispute with China on barley tariffs, signalling goodwill to work on differences in how to approach Beijing.
The Australian leader met Ms Ardern at the Rees Hotel, where Maori leaders led a heartfelt and sometimes humorous "powhiri", a formal Maori welcoming ceremony.
On arrival, the pair engaged in the traditional Maori greeting, touching noses and sharing breath.
Quarantine-free travel between Australia and New Zealand began last month after both nations controlled the spread of Covid-19, allowing Mr Morrison and Ms Ardern to meet in person for the first time in 15 months.
The talks were likely to be challenged by differences over China, the biggest trading partner of both countries, with Australia at loggerheads with Beijing and New Zealand taking a more accommodating approach.
China has in recent months moved to restrict imports of Australian products such as barley, wine and beef, with the World Trade Organisation, saying on Friday it would establish a dispute settlement panel to resolve the barley row.
Ahead of Mr Morrison's visit, New Zealand Trade Minister Damien O'Connor said his government was backing Canberra in the spat.
"New Zealand is participating in this dispute as a third party because it raises systemic issues of importance to the effective functioning of the multilateral rules-based trading system," local media cited Mr O'Connor as saying.
"New Zealand was not asked to join as a third party, however we have been a third party in over 60 WTO cases since 1995 and it's not unusual for us to join actions disputes when we see challenges to international trade rules."
New Zealand's strengthening ties with China
Australia's ties with China have sunk to their lowest point in decades in the past 18 months after Mr Morrison led calls for a global enquiry into the origins of Covid-19 and Australia barred Chinese tech giant Huawei Technologies Co from its 5G network.
New Zealand's economic ties with China have been strengthening, with the two countries this year upgrading their free trade agreement.
New Zealand also said last month it was "uncomfortable" with expanding the role of the Five Eyes, a post-war intelligence grouping that also includes the United States, Britain, Australia and Canada.
This raised speculation Wellington did not back the group's recent criticisms of Beijing.
China has accused the Five Eyes of ganging up on it with statements on Hong Kong and the treatment of Muslim Uyghurs in Xinjiang.
Formal talks between Ms Ardern and Mr Morrison, expected to be dominated by China and its growing influence in the region, are to take place on Monday.
Ardern wants to write 'Covid-19 rulebook' with Australia
Mr Morrison said the Australia-New Zealand partnership "will be even more vital in the years ahead as we both confront an increasingly challenging geostrategic environment".
"These talks will be an important opportunity for us to continue our efforts to support an open, inclusive and resilient Indo-Pacific," he added.
Mr Morrison has referenced a possible biosecurity deal being announced on Monday.
Both leaders are expected to discuss their rollout of Covid-19 vaccine in the Pacific after committing 7.5 million doses to the developing region.
Addressing business leaders on Sunday night, Ms Ardern said she was most eager to talk about the next phase of Covid-19 planning.
"The path that New Zealand and Australia carved (during Covid-19) was unique, and it continues to be unique," Ms Ardern said.
"That however means there is no rulebook for us.
"We're both looking forward to the next day of talks, that next stage of writing the rulebook.
"As we both grapple with the challenge of how we safely re-open ourselves up to the world, whilst holding on to all the gains we've made, those are conversations that I would love to be able to have together - to write that rule book together."
– with AP, AAP
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