Anthony Albanese has praised his New Zealand counterpart as a woman who led with "intellect and strength" after her shock resignation.
Jacinda Ardern announced on Thursday she will retire from politics in February, as she revealed New Zealanders would go to the polls on October 14.
The prime minister said Ms Ardern had "shown the world how to lead with intellect and strength".
"She has demonstrated that empathy and insight are powerful leadership qualities," he wrote on Twitter.
"Jacinda has been a fierce advocate for New Zealand, an inspiration to so many and a great friend to me.
"I wish (her) and her family well in the next chapter of their lives."
Mr Albanese added he looked forward to working with the new leader.
Relations between the two countries went through a bumpy patch under Scott Morrison's prime ministership, particularly over immigration and refugee issues, the treatment of New Zealanders living in Australia, COVID-19 border settings and different takes on China.
Since 2014, Australia has used the Migration Act to cancel visas for NZ residents on criminal or character grounds.
Thousands of New Zealanders have been handed a one-way ticket across the Tasman over the past nine years.
But the election of the Albanese government last year was widely seen as a "reset" in the relationship.
The pair had worked on giving Kiwis living in Australia more rights, including being able to vote and gain an easier pathway to citizenship.
There are also plans in train for annual bilateral meetings between key ministers.
But the trans-Tasman neighbours haven't been in lockstep on everything, after differences emerged in Pacific migration plans at last year's Pacific Island Forum.
Mr Albanese said he is pushing to implement Australia's first Pacific-specific migration plan as his government works to deepen ties in the region.
Labor's pledge will see a ballot run each year, with 3000 places for citizens from the Pacific and East Timor.
New Zealand scrapped a plan to preference Pacific migration, a move Ms Ardern attributed to COVID-19 at the time.
Greens senator Sarah Hanson-Young described the outgoing prime minister as a "trailblazer and a true inspiration".
"Heart felt admiration and thanks to (Ms Ardern) for showing that compassion, courage and understanding are the true strengths of leadership," she tweeted.
