Top trade representatives of 12 Pacific Rim countries are to begin two days of talks in Atlanta hoping to finalise the ambitious Trans-Pacific Partnership Agreement after July negotiations in Hawaii failed.
The United States is pushing hard for the 12-country deal to create the world's largest free trade region, hoping to lock in rules that global trade giant China would eventually have to heed.
A handful of issues bogged down the talks in Hawaii, including how the US treats imports of Japanese auto parts, the length of patent protections for increasingly important biologic drugs, and open markets for dairy products from major producers such as New Zealand.
Joshua Melzer, a trade expert at the Brookings Institution and a former Australian trade negotiator, said there was still work to do but an agreement was in sight.
"I think the prospects are good for the deal to be done this week," he said.
But nothing was certain, with vocal public groups raising objections to a number of issues under discussion and, more generally, to the secrecy of the talks.
In Ottawa on Tuesday, tractor-driving dairy farmers with a handful of cows blocked roads to Canada's parliament to protest against the possible opening up of the country's milk market to imports under the TPP.
The meeting of the trade ministers from the 12 TPP countries - Australia, Brunei, Canada, Chile, Japan, Malaysia, Mexico, New Zealand, Peru, Singapore, the United States and Vietnam - will follow four days of detailed discussions between their negotiators in the southern US city.
A deal would lower trade and investment barriers and strengthen intellectual property protections in countries comprising about 40 per cent of the global economy.
According to a study by the Peterson Institute for International Economics in Washington, the stimulus from the TPP pact could add US$295 billion (NZ$463.23 billion) in annual global income after the 10-year implementation period.
Canberra's Trade Minister Andrew Robb told the Australian Financial Review that 90 percent of the issues had been settled going into this week's discussions.
"There are unresolved issues, but hopefully these aren't intractable," he said. "A conclusion remains within imminent reach."
Melzer said that even if a deal is reached this week, it will be months before it goes to government's for ratification.
For the United States, that could mean that a potentially hostile Congress receives that pact in April or May, just as the 2016 presidential election hits high gear.