"I'm advised at this stage they [Customs] have not identified anyone [as being a contact].
"I would say though that equally we would make the call out to anyone who is from that location of interest, they may well have been contacted by health authorities in the Northern Territory to contact us, but equally we're doing the manual checking on our side as well."
NSW has also been forced into a lockdown because of the Delta variant of the virus, with increasing daily cases. Ardern said authorities here had always factored in the worst-case scenario into decision-making.
"So essentially we have that option of less regrets. So for Wellington, even though we knew where the case had come from, we knew those locations of interest, we did take a precautionary approach because we made the assumption of the Delta variant."
She said NSW had often relied on contact tracing with fewer restrictions to manage their cases.
"Our view has always been that the precautionary approach sometimes does require the short, sharp lockdown - that hasn't been their practice."
Asked if that meant a higher alert level if community transmission was found here as a result of the Australian visitor's case, Ardern said they would step up the response in line with the evidence.
"That is actually in keeping with our strategy. But you would step up [the response], depending on for instance if it was someone who was already in isolation, that would be different to someone who say for instance was not in isolation."
For New Zealanders trapped in Australia due to the suspended travel bubble, Ardern said the pause would allow authorities to assess each state's situation with community cases, their level of border restrictions with NSW, and whether or not pre-departure testing would be required for different states.
"Some of our thinking is actually that ultimately in some cases, particularly when you've got this almost starburst event that's occurred in NSW, and cases are being identified in other parts of the country, just whether or not it gives you a little bit of extra comfort - so yes, we are looking at whether we need to institute pre-departure testing.
"It's not a fail-safe, because you do it within a 72-hour period, so of course there's always risk up until you leave. But we need to factor in that in most states what they're dealing with at the moment is relatively minor, but we just wanted to take that pause to assess each state given the number of cases that have been dealt with."
