Pope prays alone for the millions of Latin Americans affected by migration to the US

At the border of Mexico and the United States, Pope Francis blessed a large cross in memory of all the people who have crossed the frontier.

The pope said nothing, but he clasped his hands tightly in prayer and bowed his head in silent prayer. He left a bunch of flowers on a table in front of the cross. Then, to the great joy of people, including immigrants, gathered in El Paso, Texas, on the other side of the fence, the pope waved.

The whole thing lasted less than three minutes. But with hundreds of thousands of people waiting in a fairgrounds nearby for Mass, the pope was intent on taking the time to acknowledge the significance of the spot.

At the foot of the large cross were three small crosses, which the pope also blessed. They will go to the dioceses of El Paso, Ciudad Juarez and Las Cruces, New Mexico.

According to the Pew Research Center, there were 11.3 million unauthorised immigrants in the US in 2014 - which makes about 3.5 per cent of Mexico's population. Mexicans make up about half of all unauthorised immigrants, the centre said in a report in November, though their numbers have been declining in recent years. There were 5.6 million Mexican unauthorised immigrants living in the US in 2014, down from 6.4 million in 2009, the Pew Research Center reported.

But it is not only Mexicans who are crossing the border. More and more of the immigrants apprehended by the US Border Patrol are from violence-torn Central American countries, particularly El Salvador, Guatemala and Honduras. According to figures released by the US Border Control, 4,353 people have died trying to cross the border from 2005 to 2015.

Cardinal Sean O'Malley of Boston, one of several US bishops at the pope's Mass in Ciudad Juarez, said the pope's brief moment at the border memorial was "a great sign of hope for families separated and suffering". With 20 years' experience ministering primarily to migrants, the cardinal said he can guarantee, "they bring an energy and a work ethic and a spirit of adventure that made America a great country."

Across the border at a simultaneous event in El Paso, Archbishop Joseph E. Kurtz of Louisville, Kentucky, president of the US Conference of Catholic Bishops said that the Mexicans crossing the border are first of all human beings, and in all cases they need to be treated with respect, compassion and dignity.

"We need to make room for the message of the Holy Father, we don't need to restrict it and make it into something that is simply political," the archbishop said. "Moral things have political implications, we know that, but more basically, this is a moral dimension."

He also said that he "would love to see the immigration 'debate' move to 'dialogue.'"

"And dialogue doesn't preclude that people might have different opinions," Archbishop Kurtz said. "Dialogue says, 'As I bring my convictions, let me test them with reality and make sure that I'm seeing the people with whom I'm in dialogue so that we can come up with the lasting solutions.'"

Lily Limon, of Our Lady of Mount Carmel Parish in El Paso, whose parents were immigrants from Mexico, put her hand over her heart as she saw the pope bless the border.

"To know that he was this close to us, and he took time to bless and look over to us, to the VIPs seated here, our immigrants, our young people that have crossed over undocumented, our migrant workers, this is just an incredible gesture and for us and unforgettable experience."

There were about 550 people seated on the US side of the Rio Grande taking part in the Mass.