Agriculture leaders in Iowa and around the United States applauded a preliminary trade agreement signed last week by the United States and Mexico. But, they said, it was important to also finalize an agreement with Canada to ensure continued strong trade with both North American neighbors.

“NAFTA (the North American Free Trade Agreement) binds North America and has worked very well for U.S. agriculture, and it’s important that it remains intact,” said Craig Hill, president of the Iowa Farm Bureau Federation. “We’ve worked hard over the years...