WASHINGTON • Trade ministers for the United States and 11 other Pacific nations gathered in Atlanta on Wednesday to try to reach agreement on the largest regional free-trade pact.
But knotty differences persist, and anti-trade blasts from US presidential candidates have not eased prospects for any deal.
The talks in a downtown Atlanta hotel are picking up where ministers left off two months ago after deadlocking at a Maui resort, at odds over trade in pharmaceutical drugs, autos, sugar and dairy goods, among other issues.
The proposed Trans-Pacific Partnership would liberalise trade and open markets among a dozen nations on both sides of the Pacific, from Canada to Chile and Japan to Australia, that account for about two-fifths of the world's economic output.
US negotiators said last week that enough progress had been made in recent contacts to justify hosting another, perhaps final round. Yet if the Atlanta talks yield no agreement by the weekend, the Americans are unlikely to declare failure.
Several countries, especially Australia, have opposed the United States and its pharmaceutical industry for insisting that companies' drug data be protected for 12 years to create financial incentives to innovate.
For President Barack Obama, who cited the potential agreement during his address this week to the United Nations, success in a negotiating effort as old as his administration would be a legacy achievement.
Time is not his friend, however. Even if an agreement is reached this week, Congress will not debate and vote on it until late winter - in the heat of the states' presidential nominating contests - because by law Mr Obama cannot sign the deal without giving lawmakers 90 days' notice.
He will need bipartisan support, given the resistance of many Democrats and union allies to such trade accords.
But presidential candidates in both parties have already registered strong opposition. The Republican front runner, Mr Donald Trump, the billionaire who boasts of his own deal-making prowess, has called the emerging Trans-Pacific agreement "a disaster".
While some Republican rivals also are critical, it is the rhetoric of Mr Trump, given his celebrity appeal, that has Republican leaders more worried that a toxic trade debate could threaten vulnerable Republicans next year. Senator Mitch McConnell of Kentucky, the majority leader, supports a Pacific accord but nonetheless wants to protect his narrow Republican majority - and deny Mr Obama an achievement.
On the Democratic side, where unions, progressive groups and many members of Congress oppose an agreement, Mrs Hillary Clinton has not taken a stand, though she repeatedly promoted the Pacific accord as secretary of state.
In June, Mrs Clinton told an Iowa audience "there should be no deal" if congressional Democrats' concerns for workers were not addressed, and many in the party, including administration officials, expect she ultimately would oppose a deal, like her rival, Senator Bernie Sanders of Vermont.
Should a deal come together, central to the White House campaign to sell the agreement to Congress would be the argument that setting economic, labour and environmental standards in the Pacific region would counter China's influence, officials said.
Several issues continue to block a deal. Dairy market rules divide the US, Canada, Australia and New Zealand. Also divisive are provisions over auto exports, including requirements that autos have a certain percentage of parts made in countries that are parties to the agreement.
Perhaps most contentious are negotiations related to protections for pharmaceutical companies' drugs. Several countries, especially Australia, have opposed the US and its pharmaceutical industry for insisting that companies' drug data be protected for 12 years to create financial incentives to innovate.
Critics say this keeps lower-cost generic drugs and "biosimilars" off the market for too long.
NEW YORK TIMES