Jacinda Ardern says there is "nothing to suggest" a need to move COVID-19 alert levels following a new case in the community.
In a stand-up on Sunday Ardern said the new case is an example of the Government's testing and tracing system working.
The case is a man who works on vessels at New Zealand's ports - he was being tested fortnightly when he developed respiratory symptoms on Friday and immediately sought a test before going home to isolate.
Ardern says she is confident New Zealand can remain at alert level 1 "at this stage".
She says the man was already considered to be at high risk due to his job and so was being tested regularly.
"He was between cycles of his testing regime and was due to be tested on Friday," she says.
"It is an example of the system working."
Health Minister Chris Hipkins was informed of the case at 6:11pm on Saturday but the case was not announced to the public until a 1pm briefing on Sunday. Ardern says this was normal procedure, as any new cases would usually be kept until the following days briefing.
"I am absolutely confident that we have done everything we usually do," she says.
The news of the COVID-19 case follows a landslide victory for Ardern's Labour Party in the 2020 general election.
The party garnered 49 percent of the vote translating to a total of 64 seats in Parliament.