"Despite best efforts, unfortunately, I've joined the rest of my family and tested positive for Covid-19," Ardern posted on social media on Saturday morning.

Ardern has been isolating at home with her family since Sunday when her fiancée Clarke Gayford tested positive.

"We've been isolating since Sunday when Clarke first tested positive. Neve (Ardern's daughter) tested positive on Wednesday, and I returned a weak positive last night and a strong one this morning," said Ardern.

"To anyone else out there, isolating or dealing with Covid, I hope you take good care of yourselves," said Ardern.

New Zealand recorded 7,441 new community cases of Covid-19, 2,503 of which were reported in the largest city Auckland, the ministry of health said on Friday.

To date, the country has reported 1,026,715 confirmed cases of Covid-19 since the beginning of the pandemic.