In a brief letter to lawmakers, Robert Lighthizer, the newly confirmed United States trade representative, said the administration aimed to support economic growth and better-paying jobs through unspecified improvements to Nafta that would modernize the 23-year-old agreement. But the notice — a drastically scaled-back version of a draft the administration circulated this year — promised no major modifications of the sort that the president has hinted he will seek.
Mr. Trump had threatened to withdraw completely from the agreement, only to relent in late April when the leaders of Canada and Mexico, the other parties to the deal, called and asked him to renegotiate instead. Sonny Perdue, his secretary of agriculture, also presented Mr. Trump with a map illustrating the potential negative consequences for American farmers if the deal were shut down.
The president, whose campaign-trail vows to tear up Nafta appealed to his base of disaffected working-class voters aggrieved by globalization, is under mounting pressure to follow through on his pledge. But Mr. Trump faces stiff resistance from business-minded Republicans in Congress and sectors that fear major changes would disrupt well-established supply chains and harm their bottom lines.
