The 25% tariffs, which Trump first threatened in November to demand Mexico and Canada stem the flow of fentanyl and illegal immigrants into the U.S., were among the first foreign policy obstacles for Sheinbaum, who took office in October as Mexico's first woman president and promised to keep a "cool head" during tariff talks.

President Donald Trump signed an order to put tariffs on U.S. neighbors Canada and Mexico, as well as China, starting Tuesday.

Claudia Sheinbaum, Mexico’s first female president, has made concessions to President Donald Trump on immigration and fentanyl. But she’s also firing back.

Markets are betting Mexico can keep buying off trade threats with border cooperation. But President Claudia Sheinbaum is still grappling with her country’s own problems.