Mexico’s President Claudia Sheinbaum reacted Saturday to a letter from U.S. President Donald Trump announcing new tariffs to be imposed on her country.

Her government has been unable to defuse the threat of stinging U.S. tariffs, in large part because of the White House’s focus on whether Mexico can take on the entrenched cartels feeding fentanyl and...

Mexican officials warned that the import tax would cause food shortages in the United States and called it a “strategic mistake.”