Jacinda Ardern
© Mark Mitchell/New Zealand Herald via APNew Zealand Prime Minister Jacinda Ardern
Prime Minister Jacinda Ardern has extended New Zealand's strict nationwide Covid-19 lockdown saying the current outbreak of the Delta variant of the coronavirus had not yet peaked.

The level 4 national lockdown was extended by three days until midnight on August 27 while Auckland, the epicenter of the outbreak, will have restrictions in place at least until August 31.

"The safest option for all of us right now is to hold the course for longer," Ardern said at a news conference.

"If the world has taught us anything it is to be cautious with this variant of Covid-19," she added.

Ardern said contacts in the community by people infected with the Delta variant were reported all over the country.

There are more than 320 locations of interest linked to the outbreak and 13,000 contacts have been recorded, far more than in previous outbreaks.

"Delta has changed the rules of the game," Ardern said.

New Zealand earlier in the day reported 35 new cases of Covid-19 taking the total number of infections in the outbreak to 107.

The health ministry said in a statement that 33 new cases are in Auckland and two are in the capital Wellington.

It comes after Prime Minister Scott Morrison said Australia will stick to its lockdown strategy against the coronavirus until at least 70% of its population is fully vaccinated, but after that it will have to start living with the virus.

The country set a record with 914 infections, its highest daily figure, as the southern and eastern states of New South Wales, Victoria and the Australian Capital Territory remain under a strict lockdown.

"You can't live with lockdowns forever and at some point, you need to make that gear change, and that is done at 70%," Morrison said in a television interview on the Australian Broadcasting Corp's Insider program.

Lockdowns are a key element of the federal government's strategy to rein in outbreaks until the 70% percent level is reached, with borders being re-opened gradually when the figure climbs to 80%.

But in a departure from the zero-Covid strategy adopted since the pandemic began, Morrison said it was highly unlikely for Australia to reach zero cases before curbs can be eased.

"Lockdowns are not a sustainable way to deal with the virus and that's why we have to get to the 70% and 80% marks, so we can start living with the virus," he added.

About 60% of the population of 25 million is now under lockdown. Stay-at-home orders, often lasting for months, have taxed the patience of many.

Police in the most populous state of New South Wales said they handed out 940 fines in the past 24 hours for breaches of public health orders, while media said several hundred people gathered to protest Sunday curbs at the Queensland state border.

This follows hundreds of arrests made by police on Saturday during anti-lockdown demonstrations in Sydney and Melbourne, the capitals of the two most populous states, New South Wales and Victoria, which are under a strict lockdown.