Trump posted two letters Saturday morning to his Truth Social account, which were addressed to European Commission President Ursula von der Leyen and Mexican President Claudia Sheinbaum, informing them the Trump administration is imposing a 30% tariff rate on their imports.

The tariffs are slated to kick in on Aug. 1, and do not include any separate tariffs on specific sectors, like steel or automobiles.

The 30% rate on the EU is unexpected, as reports suggest the bloc had been in the process of negotiating a deal with the Trump administration in which they would have kept the existing 10% tariff rate in place, and European officials believed they would not receive a letter imposing a new tariff rate on them, as other countries had.

Trump’s letter to Mexico cited the country’s failure to deal with the flow of fentanyl from its drug cartels into the U.S., with Trump writing, “Mexico has been helping me secure the border, BUT, what Mexico has done, is not enough.”

It’s unclear if the 30% rate could change before Aug. 1: Trump’s letter threatens his administration will raise the tariff rate further if either the EU or Mexico decides to retaliate, and both countries are likely to pursue further negotiations with the Trump administration before the Aug. 1 deadline.

Trump suggests he could also lower the 30% tariff rate if they get rid of their trade barriers for U.S. imports—or, in Mexico’s case, completely stop the flow of fentanyl into the U.S.