Speaks at a press conference in Wellington, she said the elections now will be held on 17th October.
The vote was due to take place on 19 September but will now be held on 17 October instead.
Jacinda Ardern said on Monday that the new announced date would allow parties “”to plan around the range of circumstances we will be campaigning under”.
“This decision gives all parties time over the next nine weeks to campaign and the Electoral Commission enough time to ensure an election can go ahead,” Ms Ardern said, adding that she had “absolutely no intention” of allowing any further delays to the vote.
The opposition National Party has argued the election should be delayed as restrictions on campaigning mean Ms Ardern had an unfair advantage.
Auckland were restricted on Wednesday after a number of new infections were identified in the city.
9 new COVID-19 cases were confirmed on Monday, bringing the number of active cases linked to the Auckland cluster to 58.