Covid-19 Minister Chris Hipkins says the travel bubble with Australia could be up and running next month.
The government will reveal the start date for a trans-Tasman travel bubble on 6 April.
Yesterday, Prime Minister Jacinda Ardern said more time was needed to nail down the final details.
"I'm optimistic that we might be able to get something up and running in April but we've just got to work our way through those remaining issues..." Chris Hipkins told Morning Report.
There are visa and logistic issues to resolve but the bubble should be just weeks away, he said.
He said trans-Tasman airlines need more time to prepare, and Auckland Airport is still sorting out its separation of passengers in terminals.
"We just want to make sure that physical separation is absolutely robust."
The airport has been running trials of a new red-zone terminal which processes people outside of the green-zone, Hipkins said.
None of the problems that have arisen in the trials were insurmountable, he said.
"I'm optimistic that we might be able to get something up and running in April" - Covid-19 Minister Chris Hipkins
He said when there is a fully operational green-zone there will be very few red-zone flights left across the Tasman and the government needs to account for that, he said.
"That could potentially leave people stranded."
Ardern said the raft of things needed to be worked through between now and 6 April included a robust framework for when cases arise in Australia, the appropriate regulatory mechanisms were in place, and an up-to-date health assessment provided the Director-General of Health.
The government needed to work on contact tracing requirements, QR codes and testing as well, she said.
However, National says the government is using excuses to stall for time.
"Frankly a lot of what they're pointed to just looks like excuses," National's Covid-19 spokesperson Chris Bishop said.
"My understanding is that issues at the airport for example were sorted in October last year; Auckland airport, Wellington airport, Christchurch airport have the red-zone flights and the green-zone flights. They've talked to the Ministry of Health around that, got approval around that so they are ready to go - that's certainly what the airports are saying now."
He said airports and airlines could handle a travel bubble with just one week's notice.