Adern told a press conference that New Zealand was "ahead of schedule." The country has not reported any new cases for 11 days in a row.
She said that, while previous advice modeling had assumed there would be a "persistent and potentially longer tail of cases" as the country moved to "level two," risking further spread, so far a tail or spike in cases had not occurred.
New Zealand's cabinet will review the alert level settings earlier than planned, on June 8, Ardern said, adding "if and only if there are no further unexpected cases over the coming days, then we could be in a position to move to alert level one that week."
According to New Zealand's Ministry of Health, there is one active case of coronavirus nationwide.
According to Johns Hopkins University, New Zealand has had 1,504 confirmed cases and 22 deaths.
Arden said she will provide further details of alert level one this week, and said that the last remaining restrictions on physical distancing and restrictions on mass gatherings would be removed, though strict border controls would remain to prevent new infections arriving from overseas.
Alert level one means there would be no restrictions on domestic transport, no restrictions on gathering, and all schools and workplaces would open.
"Our strategy of going hard and early has paid off, and in some cases beyond expectation and what modeling and data had predicted."
"Moving to level one so soon, we will be one of the first countries in the world to... return to this level of normality so quickly," Ardern said.
In April, New Zealand said it had "eliminated" the virus as case numbers stayed in single figures.
New Zealand's lockdown timetable
The first case of coronavirus was confirmed in New Zealand on February 28 -- more than a month after the United States confirmed its first infection.
On March 14, when the country had six cases, Ardern announced that anyone entering the country would need to self isolate for two weeks, which at the time was among the toughest border restrictions in the world. Foreign nationals were banned from entering the country on March 20.
Days later on March 23 -- with no deaths and when there were 102 confirmed cases -- Ardern announced the country was entering "level three" lockdown. Non-essential businesses were closed, events and gatherings canceled and schools closed to all children except those of essential workers.
Employers were told to allow working from home where possible, public transport was reserved for essential workers, and discretionary domestic air travel between regions was banned.
At midnight on March 25, New Zealand moved to the strictest level 4 lockdown, with people told not to leave home except for essential exercise near the home, while maintaining two meter distancing.
On April 9, despite a decline in cases, Ardern tightened border restrictions so that all citizens and permanent residents arriving in New Zealand were required to spend two weeks quarantined in an approved facility rather than at home.
The country has also said it has one of the highest testing capacities in the world.
CNN's Alex Lin, Anna Kam and Emma Reynolds contributed to this report.