People from the Cook Islands can travel into New Zealand from January 21 without undergoing quarantine.
"Following confirmation of the Cook Islands’ Covid free status, and the implementation of strict health and border protocols, we are now in the position to resume quarantine-free travel for passengers from the Cook Islands into New Zealand," Prime Minister Jacinda Ardern said.
"These arrangements do not apply to New Zealanders wishing to travel to the Cook Islands.
"We said we would take a phased approach to resuming two-way travel and will do so only once all safety protocols can be met," she said.
Cook Islands Prime Minister Mark Brown said the one-way quarantine-free travel would allow people from the Cook Islands access to essential services, in what he added was the "lead up to resuming free movement of people in both directions".
Rules are still in place which only limits Cook Islanders and current holders of Cook Islands work and residence permits to enter the Cook Islands.
A two-way travel bubble with the Cook Islands is still being worked towards by both Governments, with an aim for it to open in the first quarter of 2021.
Before going back to the Cook Islands, they would need to take a Covid test and have a negative result within 96 hours of take off.