The finer points of the Trans Pacific Partnership are being deliberated and commentators say all countries remain keen to get the deal over the line.

Trade ministers from 12 countries are meeting in Atlanta to discuss new incentives to get the deal signed.

MORE: Key - TPP could be signed this week

The Wall Street Journal's William Maudlin said pharmaceutical industries will be the hardest nut to crack in the deal. He said negotiators have been preparing well in advance for the topic which is expected to be a lengthily debate - and one Australia will be in the middle of.

"It looks like there's a proposal out there that could satisfy the difference between the Australian and US position in terms of protection for these drugs from generic imitators which can be of lower cost," he said.

One of New Zealand's biggest concerns about the deal remains the dairy industry. Mr Maudlin said the Japanese aren't as concerned about dairy as first thought, the drug issues also sit atop their list.

He thinks it's too early to tell if the deal will be signed by the end of this week as Prime Minister John Key suspects.

Political opponents remain cautious of the deal and Labour leader Andrew Little doesn't believe there's been enough of a change in the TPP negotiations for it to be a good thing.

He's concerned Tim Groser's re-joining the TPP negotiations could mean New Zealand's backing-down, and it wasn't a good sign when he was clearly frustrated by the last negotiations.

Tariffs on imported goods and services are another issues on his mind. He wants to make sure New Zealand's access to trade deals doesn't outweigh changes to tariffs in other countries such as the US, Canada and Japan.