Pope Benedict XVI is on his way to Mexico, where criticism over the Vatican's handling of a clergy sex abuse scandal is likely to cloud his first visit to the country.
The pontiff left Rome airport on Friday morning and is due to be greeted by Mexican President Felipe Calderon when he lands at Guanajuato airport later in the day.
The head of the Roman Catholic Church, who turns 85 next month, will also visit the cities of Leon and Silao before heading on to Cuba during the six-day trip.
Benedict's trip comes at a time when national church leaders are fighting to overcome their share of the global child sex-abuse scandal, which destroyed the reputation of the most influential Mexican figure in the church.
Marcial Maciel, the founder of the Legionaries of Christ order, faced accusations that he had molested eight minors before he died in 2008. Church documents released in a book this week reveal the Vatican had been told of Maciel's drug abuse and pederasty decades ago.
Victims of paedophile priests hope to present a demand for justice to Benedict during his visit, but the pope's agenda appeared to have no plans for any meetings of this kind.
Meanwhile, the pope's followers are hoping he will deliver a strong message against violence in Mexico where the war on drug trafficking has killed 50,000 people in five years. He was expected to condemn the violence of cartels, some of whom claim to be Catholic but who are terrorising regions in the north.
The hacker group Anonymous in Mexico crashed at least two of the websites for Benedict's visit on Thursday, claiming the papal visit was a political move to support Calderon's conservative National Action Party (PAN) in the July 1 presidential election.
The pope's "visit comes precisely at the start of the electoral campaigns," said a faceless Anonymous figure in a video. "The PAN will take this as a political weapon to win the votes of millions of Catholics in Mexico."
When asked about the timing of the pope's visit, Calderon's office released a press release noting that Calderon invited the pope in 2007.
Mexico is the world's second-most populous Catholic nation, with 83 per cent of the population baptised.
It marks Benedict's first visit to a Hispanic Latin American country since becoming pope seven years ago, although he visited lusophone Brazil in 2007.
This stands in contrast to his predecessor John Paul II, who included Mexico on his first papal trip abroad and visited the country several times.
In Cuba, where the Catholic community makes up about 10 per cent of the population, the pope hopes to strengthen relations with the communist government.
While Benedict may address the issue of democracy, he will be careful to make sure his words cannot fuel dissidents, who have held a series of protests aimed at pressurising the pope into tackling the government on human rights.