UPDATED 11.58AM: An announcement of the outcome of Trans-Pacific Partnership discussions has been delayed.

Japanese Economic and Fiscal Policy Minister Akira Amari told reporters in Atlanta progress had been made on a number of sticking points in the agreement - including dairy, a crucial issue for New Zealand.

"There was major progress over the outstanding issues of pharmaceuticals, dairy products and place-of-origin rules for automobiles," he said.

A press conference was initially scheduled to be held at 9am NZT. That was delayed to 11am NZT, and has now been delayed until further notice.

A plenary session was held this morning after discussion had led many in Atlanta to think a deal was being reached.

Earlier, The Labour Party urged the government not to bow down to pressure from pharmaceutical companies in the rush to lock down the TPP.

Reports of an agreement between the United States and Australia over protections for biologic drugs have raised hopes of a final deal on the trade pact.

Japanese and other media reported on Sunday that US Trade Minister Michael Froman and Australia's Trade Minister Andrew Robb overcame differences that were the main roadblock to a final agreement.

The authoritative Inside US Trade website said the two had circulated to other ministers a compromise proposal on how many years of protection are to be accorded creators of the cutting-edge class of drugs sourced from living materials.

But acting Labour Party leader Annette King believes powerful countries like the US and their pharmaceutical lobby are pushing New Zealand to sign up to a patent extension on life-saving drugs, from five years to at least eight years. That would delay cheaper versions of latest medicines from entering the New Zealand market, she said.

"Our government must be fighting hard, along with other similar countries to keep it at five. It will have a big impact on the health of New Zealanders but also on the health of taxpayers' pockets."

"We've been fighting to keep that patent because we know that the cost will be huge to New Zealand."

A US official at the talks confirmed that "there is progress" on the issue, but would give no details.

Over the weekend, medical specialists voiced their concerns New Zealand's health system was being traded off in the talks. 

Executive Director of the Association of Salaried Medical Specialists Ian Powell said leaked documents the government hasn't done enough to protect the cost of medicines.

"When Tim Groser as trade minister began talking about having to swallow a dead rat and knowing that medicines is still one of the big contentious issues still outstanding in the trade negotiations, we became extremely alarmed."

"It's a real shame that our health system is seen as a dead rat, our public health system is a national treasure but it's being treated by this government in this trade negotiation as a dead rat."