Mexican officials — including the economy secretary, Ildefonso Guajardo, who is leading the Nafta talks — have insisted that the negotiations be confined to the content of the agreement itself, and not include immigration.
But the issues remain linked for Mr. Trump, who tweeted last month: “Mexico, whose laws on immigration are very tough, must stop people from going through Mexico and into the U.S. We may make this a condition of the new NAFTA Agreement.”
Officials from both countries met on Thursday for the first of two days of scheduled talks on a range of issues related to immigration.
Sarah Huckabee Sanders, the White House press secretary, declined on Thursday to comment on continuing negotiations but said that, on immigration, “the president does want to see Mexico step up and do more.”
Until last Friday, Mexican officials thought they had come to a compromise with their American counterparts on a key part of Nafta as they neared agreement on rules that would raise the share of an automobile’s content that has to be made in the region to qualify for zero tariffs, and rules governing the minimum wages of those working on autos, according to a Mexican government official with knowledge of the talks.
The Mexicans have been eager to finalize an accord before their presidential election, which is scheduled for July 1. The Americans, believing the Mexicans would bend on the automobile rules to get a deal quickly, insisted on a toughened position last week and the Mexicans responded by rejecting the proposal, saying they would rather have no deal than a bad deal, according to officials briefed on the talks.
Michael C. Camuñez, a former official in the United States Commerce Department, said Mr. Lighthizer was pressing last week for the three countries to come to a separate agreement on the auto industry. In return, Mexico had expected flexibility on some points of contention, he said.