A pause on quarantine-free travel with the Australian states of New South Wales and Queensland has been extended.
The government said the situation remained under constant review.
"We consider this pause to be prudent while investigations continue and until further test results are returned," the Ministry of Health said in a statement.
"New Zealand health officials met again today and determined that, at this time, there is still a need to get a better understanding of the developing situation and the number, and pattern, of cases being reported in these Australian States.
"A range of factors for each state were considered, including whether any new cases are identified, whether they were infectious in the community, and the results from Covid-19 testing of any contacts and from the wider community."
Special inbound flights from the two states are still planned to begin from Friday 9 July at 11:59pm.
The return green flights are for New Zealand citizens and Australian citizens who are normally residents in Aotearoa.
People with humanitarian exemptions and critical workers will also be allowed to board.
Anyone on these flights will need to have a negative pre-departure test taken within 72 hours of take-off.
"Travellers must also meet all the standard public health measures for travel, which include declaring they have not been in a location of interest in the past 14 days, are not symptomatic, are not a close contact and are not awaiting the results of a Covid-19 test.
"The increasing number of cases we are seeing in many parts of the world - including by our Australian neighbours - is a stark reminder that the Covid-19 pandemic is continuing. It reinforces we are taking the right approach with our precautionary actions to protect the public health of New Zealanders."
The travel pause from South Australia, the ACT, Tasmania and Victoria was lifted on Monday morning.