"We only have to look at our neighbours across the ocean to see the impact if we don't," Carter said.
"Northlanders are proud to be individuals but we are also people who respect others and respect our nation."
"It's undoubtedly a burden to carry again but we need to do the right thing. I'm sure the majority of our people will understand how important this is, for Northland, for New Zealand, for the Pacific and beyond," Carter said.
Dr Jason Smith, Kaipara Mayor said Auckland's level 3 restrictions placed Northland in a unique position nationally.
"Northland's the region most significantly affected in this story. Due to being a peninsula at the top of New Zealand, Northland has just a single land boundary and connects only with Auckland," Smith said.
Smith said it was important people were kind to each other and that they were prepared for what might happen regarding extending this week's restrictions beyond Friday.
"People need to be prepared for an extension," Smith said.
Mai said New Zealand had already stamped out the virus once. It had gone from 1575 cases to having 102 days without any community transmission.
"That shows we can manage this and I believe, stamp it down again," she said. Northland Mayors, councillors and or management have today held meetings as a result of the Auckland cases news; resurgence management plans kicking into action.
WDC management worked on its Covid resurgence plans for the organisation last week. Many council staff are working from home for the rest of the week, some of whom had been doing so since level 4 lockdown.
Those who need to be in the workplace to do their job are observing Covid-19 precautions.
Smith said Northland had a unique position nationally as it was effectively cut off from the rest of the country by Auckland's level 3 restrictions.
Essential services would be able to get through but that would not be the case for all.
"Kaipara has a very close relationship with Auckland which is right next door. Hundreds of people in places like Ruawai, Mangawhai, Kaiwaka and Paparoa commute into Auckland to work," Smith said.
Those who could not work remotely would be particularly impacted.
The civic leaders warned Northlanders should not be complacent, saying there was definite potential for a rise in lockdown levels. Preparation is under way for how to proceed should the country's 60 hour restrictions be extended.
"The reality is that we might have to do this many more times in coming months or even years," Mai said.
"As Prime Minister Jacinda Ardern said – behave as if you have Covid-19 and as if those around you have it too. Look out for family, friends and neighbours. Stay home if you're off colour. Say yes to the test.
"Some people will be hit extra hard this time. The message of kindness, solidarity and good sensible behaviour still stands."