Jacinda Ardern bid an emotional farewell on her last day as prime minister, speaking of the kindness and empathy New Zealanders have shown her, but said she was ready to be a sister and a mother.

Days after stunning the world by announcing she had "no more in the tank" to lead the country and would step down, the 42-year-old arrived at a gathering of politicians and Maori elders in the small town of Ratana, north of the capital Wellington, and was instantly surrounded by supporters seeking photographs.

"Thank you from the bottom of my heart for the greatest privilege of my life," Ardern told the gathering in a speech.

She will resign on Wednesday and be replaced by the new Labour party leader, Chris Hipkins.

Ardern, along with Hipkins and opposition politicians, were making an annual visit to Ratana, where a weeklong celebration is held for the birth of Maori prophet Tahupotiki Wiremu Ratana.

Wearing a black dress with her shoulders covered in a traditional Maori cloak, called korowai, she led members of her party onto the community grounds as a brass band played. The speeches and accompanying songs and dances that followed saw elders speak with humour and warmth about Ardern.