With the closure of New Zealand's borders at midnight last night - 12am today - the Government has introduced the most drastic move in its coronavirus playbook to date.
But some people can still come into New Zealand, including a small group of "exemptions".
Listen live to the Mike Hosking Breakfast show on Newstalk ZB - 7.35am: Prime Minister Jacinda Ardern
The unprecedented measure closes Kiwi borders to all tourists, but citizens and residents can still enter. Prime Minister Jacinda Ardern said she was increasingly concerned about international visitors refusing to self-isolate, prompting tougher restrictions.
"[Thursday's] decision stops any tourist, or temporary visa holder such as students or temporary workers, from coming to and entering into New Zealand," Ardern said.
All of the 28 confirmed coronavirus cases in New Zealand are related to overseas travel, she said.
"All of the evidence to date is that returning New Zealanders understand the requirement for self-isolation but I have become increasingly concerned that visitors to the country either may not be able to adequately self-isolate for 14 days, or choose not to and that is an unacceptable risk that we must eliminate."
There are now more than 200,000 cases of coronavirus in the world.
The Pacific, previously exempt to the rules around self-isolation, is now included in the border closure, as are temporary workers or temporary visa holders, including students.
People who have recently returned to New Zealand from the Pacific Islands are now required to self-isolate for a 14-day period.
"The Government understands that this decision will have a significant impact on the economy, which is why we have put in place a world-leading support package for business and will continue to work with and support all affected industries.
"However, such temporary measures are essential if we are to avoid the worst of what we are now seeing overseas," Jacinda Ardern said.
So, who can still come into New Zealand?
Citizens and residents
New Zealand citizens and residents returning home are allowed in, as are their partners, legal guardians or any dependent children travelling with them.
Citizenship applies to those born in New Zealand, someone who has obtained citizenship by descent - if mum or dad is a citizen, or those that are granted citizenship by the Government.
A resident is legally and permanently allowed to live in New Zealand, but they don't have all of the rights and privileges of a citizen - that means no Kiwi passport, no representing New Zealand in some international sports and exemptions to receiving some educational scholarships.
Someone who has been a resident in New Zealand for five years and meets certain conditions can apply for citizenship.
"It remains the case that the protection of the Pacific from Covid-19 is a major concern for the New Zealand Government and these measures support that," she said.
Any returning New Zealanders will still be required to self-isolate for 14 days upon entry.
Exemptions
A "small number" of exemptions to the new rules apply to a few people that aren't New Zealand citizens or residents, Ardern said earlier.
Citizens of Samoa and Tonga who need to travel to New Zealand for essential reasons fall into this category, as do "essential health workers" and those seeking to enter the country for humanitarian reasons.
Eight new cases of Covid-19 were announced on Thursday, with the total number now at 28 cases.
The new cases all relate to overseas travel and there was still no evidence of community transmission in New Zealand, Director-General of Health Ashley Bloomfield said.