Canada has been rebuffed in recent attempts to engage on the North American Free Trade Agreement with U.S. trade representative Robert Lighthizer amid talks between the Trump administration and Mexico, according to three people with knowledge of the negotiations. The Canadian negotiating team, led by Foreign Minister Chrystia Freeland, has been told that Lighthizer is focusing on negotiations with Mexico and isn’t interested in engaging with Canada at the moment, according to the people, who asked not to be named discussing private conversations.