MEXICO CITY, Mexico—Mexican President Claudia Sheinbaum condemned U.S. President Donald Trump’s newly imposed 25% tariffs on Mexican imports, calling them unjustified and harmful to both nations. She announced that Mexico would respond with countermeasures, with details to be revealed on Sunday at a public event in Mexico City’s Zocalo square.

The tariffs, which took effect overnight, mark a major shift in over 30 years of economic integration between the two countries and could have significant economic repercussions, particularly for Mexico’s automotive industry. Sheinbaum warned that U.S. consumers and businesses would face higher prices, with automakers being hit the hardest.

Mexico’s peso and stock market both fell following the tariff announcement. Meanwhile, Trump defended his decision, arguing that Mexico, Canada, and China had not done enough to curb the flow of fentanyl into the U.S. Sheinbaum countered that Mexico had taken "decisive actions" in the past month, including deploying soldiers to border hotspots and extraditing nearly 30 cartel-related criminals.

Sheinbaum plans to speak with Trump later this week, likely on Thursday, as tensions between the two trading partners continue to rise.