President Trump cast his trade accord with President Xi Jinping of China as a huge victory for American farmers, automakers and other key political constituencies — statements that helped send volatile financial markets higher on Monday and seemed intended to calm worries about the economic toll of a protracted trade war.
Yet 48 hours after the deal was struck, several big areas of contention remained unresolved and Mr. Trump appointed a veteran trade negotiator with deep skepticism toward China to lead the talks for the United States.
Mr. Trump’s choice of Robert Lighthizer, the United States trade representative, to lead the negotiations