Prime Minister Jacinda Ardern extended New Zealand's strict nationwide coronavirus lockdown on Friday, saying the full extent of the Delta outbreak was still unknown.

The lockdown will run until midnight on Tuesday, Ardern told a news conference.

New Zealand reported 11 new cases of the Delta variant of COVID-19  on Friday, bringing the total number associated with the current Auckland community outbreak to 31.

Of the new cases, eight are in Auckland and three in Wellington, the first time this community outbreak was seen out of Auckland. The three in Wellington had recently traveled to Auckland and visited a location of interest there, the country's health ministry said.

(With input from Xinhua and Reuters)