New Zealand is pausing quarantine-free travel with all Australian states and territories from 10:30pm on Saturday night to 11:59pm on Tuesday.
It comes as the outbreak in Sydney worsens and cases are being detected elsewhere in Australia, including in Victoria and Northern Territory. New Zealand officials received new advice on Saturday evening.
The announcement came from the Government at 9pm on Saturday.
"There are now multiple cases and outbreaks in Australia in differing stages of containment and the health risk for New Zealand in response to these cases is increasing," a statement from COVID-19 Response Minister Chris Hipkins says.
"As a result the Government has taken the precautionary step of temporarily widening the current pause with New South Wales to include all of Australia."
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Hipkins says the pause will allow the Government "to get a better understanding of the developing situation and to consider the potential implementation of a range of measures to make the bubble safer".
This could include pre-departure testing for all flights from Australia to New Zealand, he says.
In response to the Bondi outbreak, quarantine-free travel with New South Wales (NSW) was first paused for 72 hours on Tuesday. That was extended for a further 12 days on Thursday.
NSW reported 29 new local cases on Saturday. Premier Gladys Berejiklian said the situation in the state was "evolving" and has put Sydney into lockdown until at least July 9. There have been 82 community cases in the state since June 16, when the first case in the Bondi cluster was reported.
A total of 80 cases are now linked to the Bondi cluster and 20 of these cases are associated with the West Hoxton Park birthday party, according to NSW Health.
Victoria recorded one local case on Saturday after two on Friday. There was also one case in Northern Territory. Some states - such as South Australia - have no local cases. Some states have shut their borders to people who have recently been in NSW, unless they have an exemption.
New Zealand's decision will be reviewed on Monday, but Hipkins says the Government remains committed to quarantine-free travel with Australia.
"I acknowledge the frustration and inconvenience that comes with this pause, but given the high level of transmissibility of what appears to be the Delta variant, and the fact that there are now multiple community clusters, it is the right thing to do to keep COVID-19 out of New Zealand."
New Zealand travellers in Australia should follow the health instructions of the state or territory they are in. Anyone who was in Australia from June 21 onwards should monitor their health, and be aware that the number of locations of interest are increasing and they should be checking these regularly. It is also important that people contact Healthline should they develop any symptoms.
Wellington is currently under alert level 2 restrictions after it emerged this week that a tourist from NSW who visited the New Zealand capital over the weekend had COVID-19. While the man had the infectious Delta variant, no positive cases have been detected in the city.