A tiny gatecrasher twice grabbed centre stage from New Zealand Prime Minister Jacinda Ardern as she updated the nation on curbs being enforced to combat COVID-19.

"You're meant to be in bed, darling ... Pop back to bed, I'll come and see you in a second," Ardern told her daughter Neve after the toddler's voice interrupted her mother's Facebook livestream off camera.

"Well that was a bedtime fail, wasn't it?" the laughing prime minister told viewers.

Unabashed, Neve interjected again some time later, persuading Ardern it was time to end the Monday evening broadcast.

"I think I've covered everything that I wanted to share at this point anyway." she concluded.