Mexican President Enrique Peña Nieto responded to a question about Donald Trump by urging America to support openness and free trade instead of trying to isolate themselves from other countries. He criticized the tone of “isolationism and destruction” that was taking root around the world.

“In the past, some leaders address their societies in those terms,” he said. “Hitler and Mussolini did that and the outcome it’s clear to everyone. It resulted in devastation, and turned out to be a tragedy for mankind,” Nieto said via a translator after a reporter asked him to respond to Donald Trump’s promise to build a wall on the Southern border.

Peña Nieto made his remarks during a press conference at the North America Leaders’ Summit in Canada on Wednesday with President Barack Obama and Canadian Prime Minister Justin Trudeau.

Peña Nieto appeared worried by the growing strain of populist sentiment, which he sees as a threat to economic ties in North America.

“We have political leaders, political stakeholders that use demagoguery and have a populistic slogan, that want to eliminate and destroy what has been built, what has taken decades to build,” Peña Nieto said.

He described the populist leaders as “simplistic,” explaining that it was complex and difficult to run a country.

But Peña Nieto repeated that he would work with whatever president Americans elect.

“My government will respect fully the domestic electoral process in the United States,” he said.