"Welcome to our village wee one. Feeling very lucky to have a healthy baby girl that arrived at 4.45pm weighing 3.31kg (7.3lb) Thank you so much for your best wishes and your kindness. We're all doing really well thanks to the wonderful team at Auckland City Hospital", the Prime Minister said on her Instagram account.

Ardern, 37, became New Zealand's youngest Prime Minister when she took office through a coalition deal last year after an inconclusive election, and now becomes the first woman in the country's history to give birth while in office.

Deputy Prime Minister Winston Peters has stepped in as acting prime minister and will run the country for the next six weeks while Ardern takes maternity leave, according to an agreement they published earlier.

Ardern gave birth in Auckland Hospital, the country's largest public hospital, with her partner, television presenter Clarke Gayford, at her side.

smh.com.au