Mexican President Claudia Sheinbaum spoke to President-elect Donald Trump after he threatened to impose tariffs and she hinted at retaliation in a letter.

Even as Mexico President Claudia Sheinbaum attempts to quell concerns over Donald Trump’s threat of 25% tariffs, economists are looking glumly at the trouble ahead should the US president-elect actually follow through.

Texas Sen. Ted Cruz (R) defended President-elect Trump’s threat to impose steep 25 percent tariffs on all goods from Canada and Mexico — two key U.S. allies — pointing out that the remark produced “immediate” action.

President-elect Trump’s pledge to impose tariffs on Mexico and Canada threatens to upend decades of North American integration, a bumpy process that’s recast the two U.S. neighbors as providers of raw and finished goods for the world’s biggest economy.