But Mr Prior told the Weekend Herald there was a risk that a last-minute compromise could have produced a weak deal that failed to address the key points surrounding the issue.
Global public awareness had also swelled in the lead-up to the conference - something he felt would fuel the political drive needed to secure a lasting solution.
"It might take a year or two but I'd agree that the eventual outcome will be positive."
Foreign Affairs Minister Murray McCully felt the reserve proposed by New Zealand and the US held "a good chance of eventually finding acceptance".
He was disappointed some countries had held out against agreement over reserve, but was pleased it would be looked at again.
"It is clear that we have considerable work to do before that meeting if the joint proposal is to get across the line, but New Zealand is now well placed to play a leadership role in advancing the proposal."
The environmental coalition Antarctic Ocean Alliance was analysing what hurdles had stalled the talks.
"Over the next few months we will have discussions with each other and we will certainly be talking to different countries involved and trying to understand what the problems are and how we can move forward," said the group's New Zealand spokesman, Geoff Keey.
Kiwi film-maker Peter Young, whose Ross Sea documentary The Last Ocean is being pitched to international film festivals, hoped the stalemate could result in a new proposal that would rule out any fishing.
"We see these talks going through into next year as an opportunity to maintain momentum of our campaign - and hopefully convince New Zealand to build a stronger case," he said.
Responses
I get the impression that a marine protected area for the Ross Sea will happen, it is just a matter of time. This will not lead to a total ban on fishing in the Ross Sea but it is a step in the right direction.
Professor Bryan Storey, Professor of Antarctic Studies and director of Gateway Antarctica, University of Canterbury.
It is heartening that an interim meeting will be held in July next year to try and reach resolution although it's actually a very short timeframe to further develop arguments and an ambitious target to reach consensus.
Dr Victoria Metcalf, Lecturer in Animal Genetics, Lincoln University
The failure to reach consensus reflect politics trumping science.
Associate-Professor Clive Evans, University of Auckland
Although we're devastated by CCAMLR failure to reach an agreement, we will use this difficult situation to create an opportunity to increase the phenomenal support around the world so we get a marine protected area for the entire Ross Sea next year.
Philippa Ross, great-great-great granddaughter of British naval officer Sir James Clark Ross, who discovered the sea in 1841.
