On the eve of Pope Francis’ trip to Mexico, Presidential candidate Donald Trump came down hard on the pontiff, calling him a “very political person” who is being exploited by Mexico at America’s expense.

The Pope is leaving for Mexico just after noon on Friday, where he will visit a pediatric hospital, meet with an indigenous community in the southern Chiapas region, speak to youth and workers, and celebrate Mass at the shrine of Our Lady of Guadalupe.

Next Wednesday, on the final day of his trip, Francis will visit the border town of Ciudad Juárez, where he will participate in several events, including the celebration of a “cross-border” Mass.

On Fox Business Network Thursday morning, Stu Varney reminded Donald Trump that the Pope is going “to stand at the border” with migrants, and asked for his take on the matter.

“I think that the Pope is a very political person,” Trump responded, before adding that he thinks the Pope is being used by Mexico to advance its interests against the United States.

“I think he doesn’t understand the problems our country has,” he continued. “I don’t think he understands the danger of the open border that we have with Mexico. And I think Mexico got him to do it because Mexico wants to keep the border just the way it is because they’re making a fortune and we’re losing.”

During his stay in Ciudad Juárez, the Pope will visit the Cereso prison, meet with some 3,600 business leaders and workers, eat lunch with Catholic seminarians, and celebrate a Mass attended by both Mexicans and Americans.

The Mass is scheduled to take place at El Punto, a large field near Benito Juarez Stadium and just a short distance from the U.S. border. Organizers say that tickets will be furnished to Catholic parishes on both sides of the border for those who want to attend the Mass. The venue holds approximately 220,000 people.

“During Mass, Pope Francis will undoubtedly call attention to many realities that are lived on both sides of our U.S.-Mexico border, particularly the plight of so many migrants and refugees fleeing violence and poverty in their home countries, in search of better lives for themselves and their children,” said El Paso Bishop Mark J. Seitz in a statement.

“Pope Francis is expected to approach the U.S./Mexico divide as a symbol of the same journey taken by migrants. It will also provide him an opportunity to acknowledge the faithful on the El Paso side of the border,” he said.

Follow Thomas D. Williams on Twitter @tdwilliamsrome