REPORTING FROM LEON, MEXICO -- Pope Benedict XVI, en route to Mexico, on Friday condemned the "evil" behind drug war violence that has claimed tens of thousands of lives in the country. He also called for change in Cuba, where he will travel after Mexico.

Aboard the Alitalia jet that was bringing him from Rome to this conservative midsection of Mexico, Benedict said the Roman Catholic Church has a duty to steer people from the "false promises" that drug traffickers use to lure followers.

"It is the responsibility of the church to educate consciences, to teach moral responsibility and to unmask the evil," he said, "to unmask this idolatry of money which enslaves man, to unmask the false promises, the lies, the fraud that is behind drugs."

As is his custom, Benedict spoke to reporters on the flight, accepting a few predetermined questions.

He will be received here Friday by Mexican President Felipe Calderon and a mariachi band.

On Monday, Benedict travels to Santiago, Cuba, and Havana. Asked by a reporter on the flight about his visit to the communist island -- the first by a pope since John Paul II's historic trip to Havana in 1998 -- Benedict said Cuba had to find "new models."

"Today it is evident that Marxist ideology in the way it was conceived no longer corresponds to reality," he said. "In this way we can no longer respond and build a society. New models must be found with patience and in a constructive way."

Also Friday, the New York-based Human Rights Watch called for the Cuban government to end "repression aimed at silencing dissent" before and during the pope's visit. Dissidents, who the Cuban government view as subversives, have been beaten, arrested and otherwise harassed in recent days, human rights activists say.

Here in Leon, in heavily Catholic Guanajuato state, enthusiasm has built slowly. On Friday, thousands of mostly youthful churchgoers began lining the streets to await and greet the pope. They waved yellow and white flags, the Vatican's colors, and chanted.