EVANSTON, Ill. (AP) — Former Mexican President Vicente Fox is speaking at Northwestern University about the relationship between Mexico and the U.S.

Fox is scheduled to appear on the Evanston campus Tuesday for a speech and question-and-answer session. The event is free and open to the public, though tickets are required and may be obtained online .

Fox was president of Mexico from 2000 to 2006. He’s been a critic of President Donald Trump and his efforts to build a wall on the border of Mexico and the U.S.