"Whoever insults or speaks badly of Mexico doesn't know the country," Peña Nieto told El Universal on Monday, CNN reported on Tuesday.
"Whoever speaks badly of Mexicans doesn't know Mexicans."
Peña Nieto's condemnation comes after months of Trump pledging to build a "massive wall" across the US southern border to keep out undocumented Mexican immigrants and he has repeatedly insisted that Mexico will pay for it.
Trump has also made the topic of Mexican immigrants a rallying call at his events, telling his supporters across the country that Mexicans are "taking our jobs" and "taking our money."
On Monday, Trump didn't address the Mexican president directly, but repeated his pledge to build a wall along the US southern border.
"I love the people of New Hampshire, they have a tremendous problem with heroin," Trump said during a North Carolina rally. "And I said, 'I'm gonna solve that problem, because we're gonna build that wall!'"
Former Mexican President Vicente Fox slammed Trump's proposal to build a wall and told Jorge Ramos "I'm not going to pay for that f---ing wall," in a Fusion interview last month.
Trump said that in light of Fox's criticism, "the wall just got ten feet taller" during CNN's Republican debate last month and demanded an apology.
Fox told CNN's Anderson Cooper in a phone interview that he will not apologize and said that Trump reminds him of Adolf Hitler.
"Today, he's going to take that nation (US) back to the old days of conflict, war and everything. I mean, he reminds me of Hitler. That's the way he started speaking," Fox said.
Sentiments regarding Trump are reaching a boiling point in Mexico and last week legislators in Mexico City asked the federal government to ban Trump from entering the country, citing his comments on Mexican immigrants.
Outrage over Trump's comments about Mexicans and immigrants began as soon as the mogul's campaign took off last June.
During his speech announcing his presidential bid in June, Trump said that "When Mexico sends its people, they're not sending their best ... They're bringing drugs. They're bringing crime. They're rapists. And some, I assume, are good people."