Comments at the APEC meetings in Singapore show the Obama administration in the United States supports an eight-country free trade deal which would include New Zealand, says Trade Minister Tim Groser.
But he says a rebellion within President Barack Obama's Democratic Party over trade policy means the the deal may yet shelved.
The Trans-Pacific Partnership has been stalled since March pending a review of trade policy by the Obama administration.
The US administration has come under pressure to guarantee access for American businesses to the lucrative Asian market.
Mr Obama's trade representative, Ron Kirk, says the partnership would be the best way to guarantee that access.
Mr Groser is optimistic that the United States will eventually complete the deal and says the agreement's future could be clarified when Mr Obama arrives at APEC this weekend.