Efforts to complete a Pacific-wide trade deal by the end of this year appear slim after leaks exposed deep rifts between America and other countries over key contentious issues.
WikiLeaks has released the 96-page draft of the intellectual property chapter from the 12-nation Trans-Pacific Partnership (TPP) negotiations.
It shows that New Zealand and other countries oppose many of America's positions on tougher copyright and patent rules and cheaper access to medicines.
Free trade advocate Stephen Jacobi says that shouldn't come as a surprise and should reassure people that negotiators are defending that country's interests. He says the leak doesn't make it any easier to get a deal done.
But an opponent, Auckland University law professor Jane Kelsey, says it shows how little progress has been made in settling differences and the aim of completing a deal by the end of the year appears unachievable.
Trade Minister Tim Groser refused to comment on the leaked document on Thursday, but says he is committed to protecting New Zealand's interests.
"I've given on behalf of the Government numerous assurances on the issues of concern to New Zealanders around (drug buying agency) Pharmac, intellectual property.
"That's the brief we negotiated to and people should just bear in mind the wonderful upside of this negotiation. We're talking about increasing our exports by up to five billion dollars a year."
Mr Groser says if a deal isn't acceptable, the Government will walk away.
Opposition parties want greater transparency from the Government. Green Party co-leader Russell Norman says he fears it will cave in to American demands and New Zealanders won't know about it until it's too late.
"The danger is as the negotiations drag out in the United States (it) puts pressure on countries like New Zealand that a government like ours, which has an ideological commitment to these kind of deals, will compromise Pharmac in order to get a deal out of the TPP."
Separately, the United States government's attempts to get so-called fast-track authority, which stops lawmakers from tinkering with the deal, is being fiercely opposed by the US House of Representatives.