It's a girl.

Prime Minister Jacinda Ardern has given birth to a healthy baby girl at Auckland Public Hospital.

The baby arrived at 4.45pm and weighs 3.315 kilograms.

In a statement, Jacinda Ardern says she's sure she and partner Clarke Gayford are going through all of the emotions new parents go through, but at the same time feeling so grateful for all the kindness and best wishes from so many people.

A large media contingent has waited all day for the big event.

An instagram of the baby captioned "Welcome to our village wee one," had reached 10,000 likes after just a few minutes.

She is thanking the nation for best wishes and kindness - and says she is doing well thanks to the team at Auckland City Hospital.

News of the birth is already being flashed around the global media as a breaking story

Her office says both mum and the baby are doing well.

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.

A post shared by Jacinda Ardern (@jacindaardern) on Jun 20, 2018 at 11:14pm PDT