Australian Prime Minister Scott Morrison says it is "absurd" for regions - including New Zealand - to chase elimination forever in a Delta world.
He was commenting on some Australia states and territories that have said they will continue to pursue elimination and keep their borders closed to NSW.
"Any state and territory that thinks that somehow they can protect themselves from Covid with the Delta strain forever, that's just absurd," Morrison told the 9 News Breakfast show today.
"New Zealand can't do that. They were following an elimination strategy. They're in lockdown."
Morrison likened staying on the elimination path to living in a cave.
"Covid is a new different world. We need to get out there and live in it. We can't stay in the cave, and we can get out of it safely," he said.
"If not at 70 or 80 per cent [vaccination coverage], then when?"
Australia's plan to ease border restrictions is similar to New Zealand's, but Morrison has linked certain phases of reopening to vaccination targets of 70 and 80 per cent.
A spokesman for Prime Minister Jacinda Ardern noted the advice from an expert panel - chaired by Sir David Skegg - that said elimination was the best strategy at this stage of the pandemic.
"It's a strategy that's worked for us before and has both saved lives and ensured our economy has been stronger than many others," the spokesman said.
"Ultimately we want as many people vaccinated as possible so we can avoid having to use lockdowns in the future. This strategy is in line with the approach being taken in Australia."
The New Zealand Government does not have any vaccination targets, but plans to start a phased re-opening once the vaccination rollout is finished, and there is high enough vaccination coverage in the regions, and among vulnerable people and young adults.
But elimination will still be the goal, which means zero tolerance for any community cases and immediate efforts to stamp out any chains of transmission as soon as they appear.
That is necessary, health experts say, because health systems are poorly resourced to cope with any large outbreak, Delta or otherwise.
How long elimination remains the strategy in New Zealand once the borders start to reopen is an open question. Much will also depend on new technology such as any effective anti-virals.
Morrison said that cases will rise in Australia when the borders open up more with 80 per cent of the eligible population vaccinated.
By then, a better metric of success won't be how many community cases there are - and there may well be several hundred - but by hospitalisations and fatalities, against which the vaccines are very effective.
"It doesn't matter if 30 or 800 [cases], the conclusions are the same. We can do this safely, and we do need to do it."
With 80 per cent vaccination coverage, he said Covid-19 will be managed like any other infectious disease, such as the flu.
"We don't shut the country down for the flu ... that's what living with Covid looks like."
Earlier today, New Zealand director general of health Ashley Bloomfield said Covid-19 was far more dangerous than the flu.
"It is a far more serious illness - and even in the UK now, with the rates of infection they have with a high vaccination rate, it's the equivalent of around nine or 10 deaths a day in New Zealand.
"When you extrapolate that out, that is still way more than we get annually from influenza."
There are about 500 flu-related deaths in New Zealand each year.