Prime Minister Jacinda Ardern has been forced to postpone her wedding as the country moves to the red traffic light setting.
Speaking at an urgent press conference on Sunday, Ardern revealed all of New Zealand will move to the highest setting at 11:59pm.
It comes after nine cases in Nelson were confirmed as having the highly transmissible variant.
Ardern said the cases are all from one household and travelled to Auckland on January 13 for a wedding. The Ministry of Health is yet to identify a clear lead on an index case linking the family to the border.
Under the red light setting events such as weddings can go ahead with a gathering limit of 100 people if vaccine passes are required and a limit of 25 if they aren't.
The Prime Minister was planning to marry her fiance Clarke Gayford in Gisborne over the summer. But a shift in settings has forced her to postpone the event, she revealed on Sunday.
"Gathering limits of 100 do come in with the red settings at 11:59pm tonight so it will very much depend on the nature of the event and whether or not they are using vaccine passes, if they are not then it reduces to 25," she told reporters.
"As for mine - my wedding will not be going ahead but I just join the many New Zealanders who have had an experience like that as a result of the pandemic. And to anyone who is caught up in that scenario, I'm so sorry but we are all so resilient and I know we understand we are doing this for one another."
Ardern said many other people have had worse outcomes from the pandemic.
"I am no different to, dear I say it, thousands of other New Zealanders who have had much more devastating impacts from the pandemic," she said. "The most gutting of which is the inability to be with a loved one when they are gravely ill - that will far, far outstrip any sadness I experience."