Trade Minister Tim Groser says the Government drug buying agency Pharmac is not up for negotiation in Asia-Pacific free trade talks.

Groser and the Finance Minister Bill English have just returned from the Apec annual summit in Hawaii where progress towards the Trans-Pacific Partnership (TPP) free trade talks was discussed with world leaders including United States President Barack Obama.

Nine countries - the US, Australia, Singapore, Peru, Brunei, Chile, Vietnam, Malaysia and New Zealand - are negotiating the bloc which Japan, Mexico and Canada are now hoping to join.

The US regards Pharmac's monopoly as a barrier to free trade and there have been concerns the trade deal could weaken the agency's ability to buy cheap generic drugs.

However, Groser said today New Zealand had laid down a position which said: "Our public health system is not up for negotiation or part of any trade negotiation".

"I can't conceive of any New Zealand government changing that view.

"Pharmac is an incredibly valuable institution that provides high quality medicines to New Zealanders at very very highly subsidised reasonable prices.

"The fundamentals of that model are not up for negotiations."

Groser would not comment further, saying it was not in New Zealand's interests for him to negotiate through the media.

Asked to confirm Pharmac was not up for negotiation, Groser said "you've heard me correctly".

English said the global financial downturn meant there was increased momentum towards completing trade deals.

"Tools to grow jobs are limited. Countries can't borrow money or spend more."

Groser said it would be six months before it was clear whether Japan, Canada and Mexico could join the TPP.

Those countries had to complete a consultation phase before they could join negotiations.

"The dress code is high, it's not just about turning up."

Obama said at the summit he hoped to wrap up TPP negotiations by the end of next year.

- Fairfax NZ