President Trump, who has insisted Aug. 1 is a firm deadline for countries around the world, said that "the complexities of a Deal with Mexico are somewhat different from other Nations."

Trump has justified tariffs on goods from Canada, the top U.S. export market, by accusing it of failing to stop the cross-border flow of fentanyl, even though U.S. government data shows Canada accounts for only 1% of the fentanyl that enters the United States.