Prime Minister John Key says the Trans-Pacific Partnership (TPP) deal is not perfect but is shaping up well.

Photo: RNZ / Alexander Robertson

Trade ministers from the 12 countries involved in the negotiations will head to Hawaii this week to continue working towards finalising the Pacific Rim trade deal.

Mr Key said he was confident the TPP would be a high quality agreement.

"This has been an ongoing negotiation, and it's iteration upon iteration over a successive number of years.

"Even the deal as I last saw it, I think, is looking and shaping up quite well.

"It's not perfect, as I said to you a while ago - it didn't achieve as much as I would have liked in dairy; in other areas, it's pretty good."

Mr Key said all the countries involved could see that the deal was worthwhile, and no one was talking about walking away from it.

New Zealand's special agricultural trade envoy Mike Petersen - who will be at the talks in Hawaii - has said more movement on opening up dairy markets is needed.