New Zealand will ask Australian travellers - including PM Scott Morrison - to produce a negative test for COVID-19 if they have recently been to Victoria.
On Friday, COVID-19 Minister Chris Hipkins announced the new measure would apply to anyone who was in Victoria between May 20 and 25.
"While we don't see these travellers who have left Victoria prior to 25 May as a major risk to New Zealand, we want to ensure the risk is reduced as much as possible," Mr Hipkins said.
"A negative pre-departure test can give us a higher degree of confidence that a person will not be infectious upon arrival in New Zealand."
The testing regime will apply to Mr Morrison, who is Aotearoa-bound on Sunday.
The Australian PM visited Melbourne on May 20 as he toured the country in the aftermath of the budget.
On Thursday, New Zealand authorities brought in a legal order relating to anyone who had been in Melbourne for that five-day period, requiring them to isolate and get tested.
There were fears that could capture Mr Morrison, meaning he would not be able to participate in the Australia-New Zealand Leaders Meeting with Jacinda Ardern.
Mr Hipkins said the two governments had been cooperating to ensure the Queenstown meeting could still happen.
"All of the people who are coming on his flight, and it's a dedicated flight for him, they've all had pre-departure tests, including him," he said.
"It shouldn't disrupt his travel to New Zealand."
From next Monday, travellers who were in Melbourne this week will need to take a COVID-19 test and return a negative result within three days of catching their trans-Tasman flight.
On Tuesday, NZ suspended quarantine-free travel from Victoria in response to the growing number of community cases.
That border closure has been extended until Friday, June 4, when it will be assessed again.
Australians from other states and territories who have not been at locations of interest remain free to travel to New Zealand.