The conditions for starting to open up quarantine free travel with Australia have been met, Ardern told a press conference.
"The Director-General of Health considers the risk of transmission of COVID-19 from Australia to New Zealand is low and that quarantine free travel is safe to commence," Ardern said.
The quarantine free travel "opens up the opportunity to reconnect with loved ones and resume Trans-Tasman travel," she said.
"One sacrifice that has been particularly hard for many to bear over the past year has been the separation from friends and family who live in Australia, so today's announcement will be a great relief for many," she added.
The prime minister highlighted economic recovery and arrangement of safely opening up international travel while continuing to pursue a strategy of elimination and keeping the virus out.
However, she warned that people will need to plan for the possibility of having travel disrupted if there is an outbreak.
COVID-19 Response Minister Chris Hipkins said that to be eligible to travel to or from New Zealand on a quarantine-free flight, people must not have had a positive COVID-19 test result in the previous 14-day period and must not be awaiting the results of a COVID-19 test taken during that 14-day period.
"When those in Australia decide to come to New Zealand, they will be making a booking on a green zone flight. That means that there will be no passengers on that flight who have come from anywhere but Australia in the last 14 days. They will also be flown by crew who have not flown on any high risk routes for a set period of time," he said.