The Trans-Pacific Partnership deal is off life support and could be up and running by next year, Prime Minister Bill English says.
The original 12-country deal was dealt a near-fatal blow by US President Donald Trump who pulled the country out of it in his first days in office.
But New Zealand didn't give up, continuing efforts to keep it alive and it's gone much better than the Government had ever thought.
The remaining 11 countries around the Pacific Rim have all signed an agreement, now called TPP11, to press on with the deal at the weekend following a meeting co-chaired by New Zealand and Vietnam in Hanoi.
Member countries were in Vietnam for the APEC Summit.
The outcome pleased New Zealand's Trade Minister Todd McClay and Mr English has admitted the outlook is much better than the Government had thought just a few months ago.
"Japan's taking a lead, New Zealand's doing a lot of the work shepherding the other countries along," he said.
"Up to now, it looks as if this could all happen in the first half of next year, whereas two or three months ago we would've said there wasn't much chance," he told the AM Show on Monday.
There will be further trade talks held this year.
Mr McClay says the deal would mean tariff savings of $222 million each year.
Japan's National Graduate Institute of Policy Studies has estimated TPP11 will increase New Zealand's GDP by 3.4 percent and is worth an additional $2.5 billion to New Zealand's economy after 10 years, Mr McClay says.
On Saturday, Mr English, while on his overseas trip to Japan and Hong Kong, told The Nation there was hope the US could re-join talks with uncertainty around Mr Trump's scandal-ridden presidency.
"I think it's one of the incentives for the other 11 countries to keep going," he said.
"The US could come back to TPP if there's a TPP operating, and if it remains basically unchanged from the one that the US negotiated."
But TPP opponent, Auckland University law professor Jane Kelsey, says the hope the US will come back to the table with the same terms "is at best naive and at worst deliberately misleading".
"The US would treat the existing text as a down-payment on something even more self-serving. The desperation of New Zealand, Japan and Australia to resurrect the deal would embolden, rather than diminish their ambitions," she says.