JUDY WOODRUFF: Now: President Trump's tough talk and threats over the North American Free Trade Agreement and the push to revisit the 23-year-old deal.
It's been a central theme for the president and a source of anger and anxiety among some voters.
At the White House, John Yang starts us off.
PRESIDENT DONALD TRUMP: Rather than terminating NAFTA, which would be a pretty big shock to the system, we will renegotiate.
JOHN YANG: With the visiting president of Argentina looking on, President Trump told reporters he made his decision after talking to the leaders of Mexico and Canada.
PRESIDENT DONALD TRUMP: I was going to terminate NAFTA as of two or three days from now. The president of Mexico, who I have a very, very good relationship, called me, and also the prime minister of Canada, who I have a very good relationship. And I like both of these gentlemen very much. They called me. And they said, rather than terminating NAFTA, could you please renegotiate?
JOHN YANG: Canadian Prime Minister Justin Trudeau said today terminating the 23-year-old deal would cause a lot of problems.
JUSTIN TRUDEAU, Canadian Prime Minister: I highlighted that, quite frankly, whether or not there was a better deal to come, there were an awful lot of jobs, an awful lot of industries right now that have been developed under the NAFTA context. And a disruption like canceling NAFTA, even if it, theoretically, eventually might lead to better outcomes, would cause a lot of short- and medium-term pain for an awful lot of families.
JOHN YANG: There have been conflicting reports about Mr. Trump's intentions on NAFTA, reflecting the internal debate and division among his advisers.
Big business and agricultural interests had argued against outright canceling the deal, which brought down most trade barriers between the United States, Canada and Mexico. Unhappiness with NAFTA was a signature campaign issue.
PRESIDENT DONALD TRUMP: I'm going to renegotiate NAFTA, one of the worst trade deals ever signed in the history of our country, perhaps the worst ever signed in the history, frankly, of the world.
JOHN YANG: The move comes as the administration gets tough on trade as it nears the 100-day mark. This week, the White House announced new tariffs on Canadian softwood lumber imports, and the president said U.S. milk was being blocked from Canadian markets.
PRESIDENT DONALD TRUMP: If I'm unable to make a fair deal for the United States, meaning a fair deal for our workers and our companies, I will terminate NAFTA.
JOHN YANG: While the president said negotiations are starting today, in fact, the United States has to give legal notice of its intent to renegotiate. Then comes a 90-day period of consultation before any talks can begin.
For the PBS NewsHour, I'm John Yang at the White House.