Trade negotiators for the United States, Canada and Mexico are running out of time to complete an overhaul of the North American Free Trade Agreement, making it likely the effort won't be completed this year.
The failure to complete the deal would be a political setback for President Trump, who has repeatedly vowed to scrap NAFTA and replace it with something better.
House Speaker Paul Ryan has said that under timetables imposed by a 2015 law, the three countries need to complete a deal by Thursday if Congress is to pass a new treaty before the November midterm elections.
But negotiators remain far apart on several key issues, involving domestic auto content, dispute resolution and whether to impose a "sunset clause" requiring periodic renewal of the treaty.
Moreover, presidential elections take place in Mexico in July, and the expected winner, Andrés Manuel López Obrador, is a populist who could take a harder line on NAFTA. That could further complicate talks.
Democratic Rep. Rosa DeLauro of Connecticut on Wednesday urged negotiators to continue their talks, saying Ryan's deadline is arbitrary.
" 'The calendar made me do it' is not an excuse to quit on the American worker," she said.
Edward Alden, a senior fellow at the Council on Foreign Relations, said Ryan could probably find a way to postpone the deadline a few days if the countries were on the verge of an agreement, but that's not the case.
"They have failed to reach an agreement, and the divisions are fairly fundamental, so I'm not certain that even if Ryan comes back and says, 'I didn't really mean it, there's wiggle room,' that it's going to make a difference," Alden said.
Meanwhile, White House spokeswoman Sarah Huckabee Sanders told Fox News the Trump administration would continue the renegotiation effort, but did not address the deadline problem.
"We still want to see something happen, and we're going to continue in those conversations. They're ongoing now, and we're pushing forward and hopeful that we can get something done," she said.