WELLINGTON, AAP – New Zealand Prime Minister Jacinda Ardern has foreshadowed the return to state-by-state bubble arrangements after ordering a snap 73-hour lockdown to Australia on the weekend.

On Saturday night, a small number of ministers met and suspended quarantine-free travel with Australia, a move later attributed to fears around the case at a Northern Territory mine site.

Officials are manually checking arrivals to New Zealand against staff lists at the mine site to see whether fly-in fly-out workers have landed in Aotearoa.

Ms Ardern said none had been found prior to the border closure; the first whole-of-country closure of the trans-Tasman bubble since it opened nine weeks ago.

While there is no prospect of re-opening to NSW as it contends with its major Bondi cluster, Ms Ardern said cabinet would look at the rest of Australia today.

“As we assess … you may see different guidance for different states,” she told TVNZ.

New Zealand is on a 120-day streak without community transmission but Wellington is currently on high alert for new cases after an infected Sydney man visited the capital.

Health officials have placed more than 2000 residents into isolation after categorising them as close contacts, but mass testing has failed to show up any local cases.

Ms Ardern said the man’s wife, who also travelled to NZ, had also tested positive on return, suggesting Wellington wasn’t yet out of the woods.

“I will always maintain a very cautious approach all the way through,” Ms Ardern told TV3.