Prime Minister Jacinda Ardern and Auckland Mayor Phil Goff emerged from their first meeting together in perfect agreement.

The pair, who used to work together when Goff was still in parliament, met with Finance Minister Grant Robertson and Housing and Transport Minister Phil Twyford to discuss how the Government can work with the Auckland Council.

On the agenda included the future of the port and the fuel tax.

Ardern said she doesn't support a new proposal by Ports of Auckland that would extend Bledisloe Wharf into the Waitemata Harbour.

Speaking after her first meeting as Prime Minister with Auckland Mayor Phil Goff, Ardern was asked about the port company's draft 30-year masterplan for the 77ha of land it owns on the city's doorstep.

"What I'm happy to say is that I have always opposed port expansion at its current site," she said.

That was in reference to plans for a 13m piled concrete extension at the end of Bledisloe Wharf, which the company said is essential for a new berth and the success of the other wharf projects.

New Zealand First wants container operations moved to Northport near Whangarei by 2027, but that pledge was watered down in coalition negotiations with Labour. The coalition agreement included a feasibility study on the options for moving the Ports of Auckland, including giving Northport serious consideration.

Goff today said it would be that feasibility study that would drive the future of the port, not today's Ports of Auckland plan.

"What we have now is a study that will demonstrate what will work best for Auckland, for the region in the upper North Island and the country as a whole. I think that study is going to be the study that really counts for what we do in the future," he said.

"I welcome the fact that the Government has committed to an upper North Island port study. It doesn't make sense for Auckland to make a decision in isolation to what the region and the country needs.

"So this is a draft proposal from the ports. That will go out for public discussion. They will be seeking resource consents."

The Ports of Auckland is owned by Auckland Council.

Goff also said that Auckland rates would have to be raised by a "totally unsustainable" 15 per cent without a regional fuel tax to pay for the city's future transport needs.

Labour supports a regional fuel tax, which the previous government wouldn't agree to, and Goff said that over 10 years it could contribute between $1.2 billion and $1.5b towards paying for transport infrastructure and light rail in the city.

"We're adding 800 cars a month to roads in Auckland, it's absolutely unsustainable," he said.

"We need to have light rail - I applaud the government for its commitment to that."

Goff said a regional fuel tax would cost the average motorist around $2.60 a week.

"If we did not have the regional fuel tax we would have to put up rates by probably around 15 per cent, which would be totally unsustainable, or introduce a congestion tax."

Ardern said a regional fuel tax, which needs government approval, was something she was "happy to offer".

Goff said the Special Housing Areas created by the previous government weren't solving the affordability problem but Labour's Kiwibuild programme would make a huge difference.

The aim is to build 100,000 affordable houses over 10 years, with half of them in Auckland.

Goff, who was Labour Party leader during Ardern’s first term in parliament, hugged his former colleague as they arrived at the media scrum.

Goff said it's good to be back.

"I'm almost feeling nostalgic about the place - almost," he stressed to laughs from his former colleagues.

- NZ Herald with content from NZ Newswire