New Zealand Prime Minister Jacinda Ardern participates in a televised debate with National leader Judith Collins at TVNZ in Auckland, New Zealand, on September 22, 2020. File Photo: Fiona Goodall/ Pool via Reuters

New Zealand Prime Minister Jacinda Ardern announced a nationwide lockdown on Tuesday after a new case of Covid-19 was discovered in the biggest city of Auckland.

The lockdown will run seven days in Auckland, but three days elsewhere. Ardern said authorities were assuming the new case was a Delta variant although this has not been confirmed.