Mexican President Claudia Sheinbaum says that the incoming U.S. president’s plan to institute massive tariffs on Mexican imports would bring about mutually assured economic destruction.

President Claudia Sheinbaum suggested Tuesday that Mexico could retaliate with tariffs of its own, after U.S. President-elect Donald Trump threatened to impose 25% import duties on Mexican goods if the country doesn’t stop the flow of drugs and migrants across the border.

Mexican President Claudia Sheinbaum on Tuesday warned U.S. President-elect Donald Trump of dire economic consequences for both countries from tariffs and suggested possible retaliation following his threat of across-the-board tariffs of 25% on Mexico and Canada.