September could be a "realistic" time frame for New Zealand's borders to open up to Australia, Prime Minister Jacinda Ardern says.
The expert working group developing a blueprint for how a trans-Tasman bubble would work has said it could be operational by September.
Ardern said today that date could be achievable.
"I think that could be realistic. I have been careful about putting down specific dates. But I have been very focused on making sure that as soon as we are ready then we can move.
"Needless to say [Australian] Prime Minister [Scott] Morrison and I are very, very keen to see us moving towards an opening up of our borders as soon as it's safe to do so, but we are just giving ourselves the space to make sure that we are ready to go, that we are safe, and that we're not going to export risk to one another," Ardern said.
However, Deputy Prime Minister Winston Peters is still agitating for a move much sooner.
In the House today, Peters answered questions from National deputy leader Nikki Kaye on behalf of the prime minister.
When asked if Peters had advocated Ardern to proceed faster around the trans-Tasman bubble, Peters replied: "Take a wild guess."
Kaye then asked what time frame Peters was advocating for, he said: "In one word: yesterday."
New Zealand First has also been at odds with its coalition partner over the timing of the move to alert level 1, with Peters saying on Wednesday that New Zealand should already be in the lower alert level.
Cabinet will review the level 2 settings on 8 June, and will look to move to level 1 no later than 22 June if cases remain low.
Ardern stood firm on this timeline today, despite another day of no new cases, and there only being eight active cases in the country.
"It is the Director-General's advice that we're acting on and so he's comfortable with those time frames, but we have given ourselves space just in case on 8 June he may recommend that there could be some relaxing within alert level 2.
"We have moved and are opening up much more rapidly than other countries but we don't want to jeopardise the very privileged position New Zealanders have earned. And they worked hard to get us here and I don't want us to lose that," she said.