From the Document: "Congress has maintained significant interest in Mexico, an ally and top trade partner. In recent decades, U.S.-Mexican relations have grown closer through cooperative management of the 2,000-mile border, the North American Free Trade Agreement (NAFTA), and security and rule of law cooperation under the Mérida Initiative. Relations have been tested, however, by President Donald J. Trump's shifts in U.S. immigration and trade policies."
CRS Report for Congress, R42917
Congressional Research Service: https://crsreports.congress.gov/