Watch live coverage of Pope Francis' trip on CNN.

(CNN) Holy hairdo! This portrait of Pope Frances shaved into a man's head was done by Philadelphia barber and salon co-owner Kenny Duncan.

Duncan tells CNN he is a fan of the Pope and wanted to celebrate his visit to Philadelphia. "The Pope is near and dear to my heart," says Duncan, who is not a Catholic but says he respects the Pope and the morals he promotes.

The haircut took just over an hour to complete. The trick to the Pope's gray hair? White hair fibers attached with a temporary adhesive. The hair model is a fellow barber at Duncan's salon, Main Attraction Unisex Salon, in West Philadelphia.

Duncan, who specializes in hair portraits, is also a barber educator and organizer of "Barbers Who Care," an annual community event offering free haircuts to young boys in Philadelphia. Of that, no doubt, the Pope would approve.

To see all of CNN's coverage of the Pope's six-day visit to the United States, visit CNN.com/PopeFrancis . Here's a glimpse of what CNN reporters in the field are seeing:

A cake for the Pope

This cake, posted to Instagram by cake decorator Deric Moniz, was made for the Pope's visit to Curran-Fromhold Correctional Facility on Sunday.

The prison is the largest facility in the Philadelphia prison system. During his visit there, Francis will greet some of the prison's inmates, family members and staff.

Kristee Johnson, manager of L&M Bakery in Delran, New Jersey, tells CNN the bakery got the opportunity to make this cake because an employee's husband works for the prison.

Johnston says the cake will be presented to the Pope in a separate room after he's completed his visit with inmates. According to Johnson, the bakery worked with the secret service for months to clear the cake being brought into the facility.

#cake for #popefrancis as visits a #prison in #Philadelphia #popeinphilly #buttercream #portrait #fall A photo posted by Deric Moniz (@jdmoniz) on Sep 26, 2015 at 1:59pm PDT

What's in the Pope's bag?

When Pope Francis enters and leaves the papal plane, he's usually seen carrying his own bag.

So what's in his carry-on?

Pope Francis carries his bag off the plane.

CNN's Rosa Flores reports that the bag holds an electric razor, a prayer book, a novel, a rosary and a tooth brush.

How Francis fans greeted Trump

Everyone knew Pope Francis' visit to New York City would be "YUUUGE," so it's no surprise that as massive crowds gathered Thursday along Manhattan's Fifth Avenue, hoping for just a glimpse, Republican presidential hopeful Donald Trump was seen out on the Fifth Avenue balcony of Trump Tower headquarters.

In fact, it seems many of the faithful gathered below were less than happy to see him. An undeniable sound of "boos" greeted the famous New Yorker.

One imagines Pope Francis, who preaches the Golden Rule, wouldn't approve of the heckling.

But Trump fans and Francis fans might see a few things differently. At a speech to Congress in Washington hours earlier, Pope Francis had made a plea for politicians to to embrace millions of undocumented immigrants, calling himself "the son of immigrants." Trump has pointed to crimes committed by undocumented immigrants in the United States and claimed undocumented workers take jobs from Americans.

Francis has called for governments to join a global campaign against climate change.

Trump has insisted that extreme weather patterns that scientists attribute to manmade climate changes are simply "weather."

JUST WATCHED What some Pope Francis fans said to Trump Replay More Videos ... MUST WATCH What some Pope Francis fans said to Trump 00:18

The Pope moment no one saw

House Speaker John Boehner choked up Friday sharing details about a private moment he shared with the Pope.

"I was really emotional in a moment that really no one saw," Boehner said during a press conference announcing his retirement.

He and the Pope were alone for a brief moment on Thursday, and the Pope shared some kind words, recognizing Boehner's commitment to children and education.

The Pope then put his arm around the Ohio Republican and asked for his prayers.

"Who am I to pray for the Pope?" Boehner said, recalling the moment while fighting back tears. "But I did."

JUST WATCHED John Boehner chokes up during resignation Replay More Videos ... MUST WATCH John Boehner chokes up during resignation 00:46

From the halls of power to lunch

Thursday began with the Pope's address to Congress . But he didn't dine with dignitaries after speaking to U.S. lawmakers. Instead, he prayed with people who rely on Catholic social services, shook hands with the homeless and blessed their lunch.

"In prayer, there are no rich or poor people," Pope Francis told them. "There are sons and daughters."

His message at St. Patrick in the City and Catholic Charities was clear.

"Today I want to be one with you," he said. "I need your support, your closeness."

And he got it.

Long after the Pope left the premises, the church and the tent outside were full of people beaming about their brush with him.

"I can't even describe it. It was the most beautiful day I ever had in my life," said Tina Thompson, 53, who's lived in a shelter for the past eight months.

The Pope touched her hand, she said, but it was so much more than that.

"He has so much love and hope, not just for some people, but for all people," she said. "He showed that he loves everybody."

"A warm and good feeling went through my body. He made eye contact with me. I felt renewed." - Andrew Gibson, who shook hands with #PopeFrancis at the Catholic Charities lunch #popeindc A photo posted by Catherine Shoichet (@catherinecnn) on Sep 24, 2015 at 10:49am PDT

Security is tight

FBI agents spent weeks going over old intelligence reports and source leads to detect any patterns or connections they might have missed that could foreshadow a potential threat against the Pope during his U.S. visit.

JUST WATCHED How will New York prepare security for Pope's visit? Replay More Videos ... MUST WATCH How will New York prepare security for Pope's visit? 03:34

"We continue to scrub and rescrub (information) just to make sure we don't have anything there looming," said New York FBI Assistant Director in Charge Diego Rodriguez.

Intelligence units from the FBI, Secret Service, New York Police Department and others have been monitoring social media, target watch lists and overseas intelligence. That data is being shared among agencies through classified databases.

Although there is no specific credible threat, there is always an implied threat.

Rodriguez -- along with the head of the U.S. Secret Service in New York, Robert Sica -- was among a handful of the city's top law enforcement officials who met the Pope as he arrived in Manhattan by helicopter before heading to St. Patrick's Cathedral.

Praying for 'a better life'

All Steven Waller wanted to do Thursday afternoon was keep playing a shark video game on a smartphone.

But reporters kept interrupting the 8-year-old after they heard about the letter he wrote to the Pope -- in crayon -- while he waited for Francis to arrive at the Catholic Charities lunch. Here's what it said: "Dear pope my name is Steven, Can you please pray for my mother, for a job and better life?"

The Pope accepted the letter, and gave him a high five.

Afterward, Steven said he liked Francis, "because he's cool" and "because my favorite color is white."

On the back of a piece of paper where he'd proudly written "Steven wins" beside many games of tic-tac-toe, he made another drawing.

"The Pope wins," it said, beside two big blue stars and a sketch of a round head with a small hat, glasses and a smiling face.

Steven Waller, 8, handed a letter to #PopeFrancis at the Catholic Charities lunch, asking for a prayer to help his mom get a job. Later, he made this drawing. #popeindc A photo posted by Catherine Shoichet (@catherinecnn) on Sep 24, 2015 at 10:32am PDT

Watching from afar, feeling the Pope near

Down the street from St. Patrick, throngs of cheering supporters squealed, screamed and chanted as the Pope's motorcade approached.

"Se ve, se siente, el Papá está presente," they shouted. You see it, you feel it, the Pope is here.

As the motorcade rounded the corner, people inside nearby office buildings pressed their faces against the window for a glimpse of the Pope. When Francis spotted them, he turned around, smiled and waved.

#PopeFrancis waves to supporters pressed against the windows across the street #PopeInDC https://t.co/qiV6ykbAbn — Catherine Shoichet (@CatherineCNN) September 24, 2015

A boost of energy

"Say Pope!" Deacon Jim Nalls said as he snapped photos of Catholic Charities clients arriving at St. Patrick Thursday morning, more than an hour before Francis was set to speak with them.

Everybody smiles.

"Say Pope!" Deacon Jim Nalls says as he snaps photos of Catholic Charities clients arriving. Everybody smiles. #PopeFrancis #popeindc A photo posted by Catherine Shoichet (@catherinecnn) on Sep 24, 2015 at 7:31am PDT

Nalls, who works for Catholic Charities, says it was the Pope's idea to visit the organization and neighboring church before he left Washington.

"He's all about this," he said. "This energizes him."

And it energizes them, too.

More volunteers have been signing up to help out lately, Nalls said -- and he suspects the pontiff may have something to do with it.

"For a lot of people that, maybe it's not a high priority on their radar, it certainly raises awareness," he said. "And people are realizing that it's important to help people out."

Secret Service agents stood guard in front of the church as police paced the area.

Outside in a nearby tent, an Irish tenor sang, "The Impossible Dream" to hundreds of homeless people gathered for lunch.

'My heart is sad'

During the motorcade on the National Mall, Pope Francis stopped to kiss babies and children. One young girl got through the barrier and handed the Pope a letter.

At first, security stopped her, but the Pope signaled for her to come over. The crowd cheered as a guard lifted her to the Pope.

"Pope Francis, I want to tell you that my heart is sad, and I would like to ask you to speak with the President and the Congress in legalizing my parents because everyday I am scared that one day they will take them away from me," she says.

"All immigrants just like my dad feed this country," she says.

Sophie Cruz,5, with her father Raùl, has memorized a message about her family for @Pontifex in English and Spanish pic.twitter.com/dhXCL4FGPv — Lauren Gambino (@LGamGam) September 23, 2015

Cruz describes herself as an "American citizen with Mexican roots." She says her parents immigrated from Oaxaca, Mexico.

Her father, Raul, had a yellow T-shirt that read "Papa Rescata DAPA!", according to the Guardian. The T-shirt's message asks the Pope to save the Deferred Action for Parents of Americans, a program that seeks to postpone deportation for undocumented parents of U.S. citizens or lawful permanent residents.

Sophie Cruz is escorted away before being called over by the Pope.

Meet the Pope

Pope Francis made two furry friends when he met Bo and Sunny inside the White House. The first pets are Portuguese water dogs. Sunny joined the family in 2013, four years after Bo arrived.

Pope Francis meets Bo and Sunny. pic.twitter.com/s0wZzdWyc0 — petesouza (@petesouza) September 23, 2015

A present for the Pope

After President Barack Obama and the Pope held a private meeting, the President presented his guest with a one-of-a-kind gift: a sculpture of an ascending dove made from metal taken from the Statue of Liberty and wood that once grew in the White House garden.

Obama also gave the Pope a key from the Maryland home of Elizabeth Ann Seton, who was the first native-born U.S. citizen to become a saint.

Not everyone is a Francis fan

Outside the Cathedral of St. Matthew the Apostle in Washington, a group of protesters from the Women's Ordination Conference gathered as reporters and parishioners lined up for a glimpse of the Pope on Wednesday morning.

Margaret Johnson led them in a song: "Sister, Carry On."

For the group from the Women's Ordination Conference, she said, it's become a rallying cry for what some hope will be a "Catholic Spring" pushing the church to treat men and women equally.

"When Pope Francis talks about the poor and people who suffer and discounts women in the same breath, his message is really without integrity," Johnson said.

The massage therapist, who's also a board member of the group, said her involvement in the organization stemmed from the Vatican's censure of U.S. nuns in 2012.

Protesters pushing for women's ordination sing outside St. Matthew, where #PopeFrancis will be praying with... https://t.co/emDxqon0RY — Catherine Shoichet (@CatherineCNN) September 23, 2015

"It really struck a nerve. I started to realize how injustice in the church is really so interconnected to injustice in the world," she said.

"When women are excluded from the Catholic Church, it morally sanctions the mistreatment of women around the world," she said.

The organization hopes protesting near places where the Pope's appearing will help spread their message.

"We're hoping that this will inspire more people to speak out. We want more and more people to speak out. People who believe in equality are not alone," said Kate McElwee, co-executive director for international relations.

Waiting on the Pope

Father Rafael Barbieri, parochial vicar at St. Matthew, said parishioners have been very excited about the Pope's visit.

"It's basically like having the Pope coming to their homes," he said.

At St. Matthew, he said, he's noticed a change since Francis became pontiff.

"Many people are coming back to the church because of the Pope," he said. "People who once were far away from their faith, they're rediscovering the sacraments."

Door just opened at Saint Matthew. Lots of anticipation that #PopeFrancis is near. #PopeInDC pic.twitter.com/syFmAvkbTY — Catherine Shoichet (@CatherineCNN) September 23, 2015

The Pope's message of mercy, he said, particularly resonates.

"To experience that God loves them but doesn't judge them."

"He's a source of inspiration to all of us."

Hours before the Pope's arrival, parishioners from St. Matthew lined up outside for a chance to hear the prayer.

"I couldn't sleep last night, knowing that he was going to be with us," said Milton Saenz, 38, who works in catering at a nearby law firm and has been attending St. Matthew for five years.

Next to him in line, Dolores Reyes, 58, was beaming as she wore a T-shirt that said: "Caminando con el Papá Francisco." (Walking with Pope Francis.)

"He seems different. He is more humble, more connected with people, with everyone. He is a great Pope. I love his approach."

Reyes, who does cleaning at a Catholic school, has been attending St. Matthew for 20 years, ever since she and her husband discovered the Spanish Mass there. Now she serves as an usher at the church.

"You can feel the love, the faith," Reyes said as she waited for her chance to catch a glimpse of Francis on Wednesday.

'You only pope once'

Thousands have been gathering between the Washington Monument and the White House since before dawn Wednesday, hoping for a glimpse of Pope Francis.

It's a carnival-like atmosphere, with folks picnicking, singing, waving banners and Vatican flags.

As in most papal visits, vendors are cashing in, selling everything from small Vatican flags to $10 T-shirts to buttons with the Pope's picture.

The throngs are diverse: many immigrants and older people, but also millennials and young professional couples with small children. All of them had their bags checked and went through metal detectors.

Pope Francis is offering hope & optimism, and challenging us to do better. Around the world, we're proud. #PopeInUSA pic.twitter.com/Ng2mgx0EmK — Vice President Biden (@VP) September 23, 2015

Bryanna Patinka, 18, a freshman at Catholic University, was with three classmates. They were practicing their "papal selfies" for when the pontiff goes by. "I want to make sure I see him," she said.

"How many times can you say you saw the Pope," asked Olivia Donahue, 18. "My mother texted me YOPO -- you only pope once!"

"He's not a Trump or a Putin," Moira Shepard, 19, said of Francis' appeal.

What to watch

The Pope holds his first public events in Washington in Wednesday. All eyes are on Francis to see how deeply he will delve into politics. After a Rose Garden ceremony, Francis and President Barack Obama are expected to meet privately in the Oval Office.

There are many issues on which both men agree -- and they seem, personally, to get along well.

But there are also issues on which the Pope and President disagree, and it will be interesting to see the statements that emerge from the private meeting.

Catholic Church sources are also keen to hear what Pope Francis will tell a big meeting of bishops Wednesday morning at St. Matthew's Cathedral in Washington.

And in his last planned event on Wednesday, Pope Francis will canonize Junipero Serra at a large Mass outside Washington's Basilica of the National Shrine of the Immaculate Conception.

The canonization is a huge point of pride for Latino Americans, and Serra, an 18th-century missionary from Spain, will be the first saint ever canonized on American soil. But to Native Americans, Serra was no saint. They say he came to conquer and convert their communities.

Photos: Few images exist of 18th-century Spanish missionary Junipero Serra, a founding figure of the American West. This portrait has become one of the standard representations of him and was done in the early 1900s by a Mexican priest, Father Jose Mosqueda, who said he copied it from a work that could have been an original portrait of Serra from the 1750s. Hide Caption 1 of 5 Photos: This is Serra's personal "novena" prayer book, which is kept in the archives of Old Mission Santa Barbara. The first page is in Spanish. Hide Caption 2 of 5 Photos: Here's another image of Junipero Serra from a first-edition book about the Spanish Franciscan friar entitled, "Relacion Historica de la Vida y Apostolica Tareas del Venerable Padre Fray Junipero Serra," by Father Francisco Palou. His book was first published in Mexico in 1787. Hide Caption 3 of 5 Photos: This is how Father Serra signed his name on a letter about the value of prayer to another Franciscan friar, Fermin Francisco de Lasuen. Hide Caption 4 of 5 Photos: Serra often corresponded about the California missions as he evangelized Native Americans in the late 1700s. This letter is written by Serra's own hand and is kept in a climated-controlled vault at Old Mission Santa Barbara. Hide Caption 5 of 5

The Pope's ride

What was that bulbous-looking car that whisked Pope Francis away from the tarmac on Tuesday?

A Fiat 500L by Fiat Chrysler Automobiles. In fact, the Pope is making good use of Fiat Chrysler wheels on his visit to the United States.

The 500L is big brother to the more familiar Fiat 500 minicar. Prices start at about $20,000.

Unlike the Fiat 500, which would have been entirely impractical for transporting a pope and his entourage, the 500L is large and roomy inside.

Nice ride!

The scoop from a papal insider

Cardinal Donald Wuerl of Washington, one of Pope Francis' closest advisers, will host his boss for a short visit starting Tuesday afternoon.

As you might imagine, Wuerl has a few planning items on his plate, but CNN managed to catch him for a quick interview on Monday. This Q&A has been edited for length and clarity.

CNN: The Holy Father's speech to Congress on Thursday is one of the most highly anticipated aspects of his visit to the United States. How deeply do you think he'll delve into U.S. politics?

Cardinal Donald Wuerl: I suspect that the themes he touches on may be familiar ones, the ones we've heard him speak about so many times in "The Joy of the Gospel" and "Laudato Si."

I would also suspect that he's going to approach this as a pastor, a spiritual leader. He may point to certain problems and our moral obligation to resolve them, especially when they touch on the marginalized.

But I would be very surprised if the Holy Father proposed any practical policies or laws.

CNN: Already one congressman has said he plans to boycott Pope Francis' speech to Congress because he may speak about climate change. How would you respond to that?

Wuerl: Nobody can really deny that there are serious problems (with the environment). We've been hearing for years about the depletion of the rainforest, the poor condition of water around the world and all the terrible famines. The Holy Father is saying we need to look at these and find a way to meet in the needs of human beings.

CNN: The boycotting congressman, who is Catholic, said: "When the Pope chooses to act and talk like a leftist politician, then he can expect to be treated like one." How would you respond to that?

Wuerl: I think the more helpful starting point is to face the issues, rather than addressing the alleged characteristics of the personality.

CNN: What message is Pope Francis sending by canonizing Junipero Serra, the first saint to be canonized on U.S. soil and a Latino, in the nation's capital?

Wuerl: There are a number of reasons for the canonization being here: First of all, it's where the Holy Father is going to be and we have the National Shrine of the Basilica here, as well as a large Spanish-speaking population.

I don't think this is directed toward a political campaign or to specific candidates, but certainly no one can deny that from the very beginning, going back to all the discovery of America, the Spanish language has been part of our history. So I don't see why Hispanics would be considered latecomers.

CNN: Before I let you go, what are you most looking forward to during the papal visit?

Photos: Pope Francis visits Cuba Photos: Pope Francis visits Cuba Security surrounds Pope Francis as makes his way to the Metropolitan Cathedral in Santiago, Cuba, on Tuesday, September 22. The Pope arrived in Cuba on Saturday and is scheduled to travel to the United States on Tuesday. Hide Caption 1 of 23 Photos: Pope Francis visits Cuba Pope Francis prays inside a sanctuary in El Cobre, Cuba, on Monday, September 21. Hide Caption 2 of 23 Photos: Pope Francis visits Cuba Residents wait for Pope Francis to drive past in Holguin, Cuba, on September 21. Hide Caption 3 of 23 Photos: Pope Francis visits Cuba The Pope celebrates a Mass in Holguin on September 21. Hide Caption 4 of 23 Photos: Pope Francis visits Cuba Pope Francis, left, blesses the communion bread during the Holguin Mass on September 21. Hide Caption 5 of 23 Photos: Pope Francis visits Cuba People cheer in Holguin as Pope Francis arrives for the Mass on September 21. Hide Caption 6 of 23 Photos: Pope Francis visits Cuba Pope Francis stands with Cuban President Raul Castro in the Revolution Palace in Havana, Cuba, on Sunday, September 20. Hide Caption 7 of 23 Photos: Pope Francis visits Cuba Pope Francis shakes hands with Fidel Castro in Havana on September 20. The Vatican described the 40-minute meeting at Castro's residence as informal, with an exchange of books. Hide Caption 8 of 23 Photos: Pope Francis visits Cuba Pope Francis walks to the altar to celebrate Mass at Revolution Square in Havana on September 20. Hide Caption 9 of 23 Photos: Pope Francis visits Cuba An enormous crowd fills Havana's Revolution Square for the Pope's Mass on September 20. Hide Caption 10 of 23 Photos: Pope Francis visits Cuba Pope Francis blesses the Virgin of Charity as he celebrates Mass on September 20. Hide Caption 11 of 23 Photos: Pope Francis visits Cuba Pope Francis kisses a child as he arrives in Revolution Square on September 20. Hide Caption 12 of 23 Photos: Pope Francis visits Cuba Crowds surround the Pope as he arrives in Revolution Square on September 20. Hide Caption 13 of 23 Photos: Pope Francis visits Cuba Pope Francis arrives at Revolution Square on September 20. Hide Caption 14 of 23 Photos: Pope Francis visits Cuba Worshippers in Havana gather before sunrise for the Pope's Mass on September 20. Hide Caption 15 of 23 Photos: Pope Francis visits Cuba Women wave from an apartment building as Pope Francis travels from the airport on Saturday, September 19. Hide Caption 16 of 23 Photos: Pope Francis visits Cuba Pope Francis waves to people as he arrives at the Apostolic Nunciature in Havana on September 19. Hide Caption 17 of 23 Photos: Pope Francis visits Cuba Crowds line the streets to greet the Pope in Havana on September 19. Hide Caption 18 of 23 Photos: Pope Francis visits Cuba Pope Francis speaks with Cuban President Raul Castro during his arrival ceremony on September 19. Hide Caption 19 of 23 Photos: Pope Francis visits Cuba Soldiers march inside the airport in Havana during the arrival ceremony for the Pope on September 19. Hide Caption 20 of 23 Photos: Pope Francis visits Cuba Children welcome the Pope shortly after he landed at the airport on September 19. Hide Caption 21 of 23 Photos: Pope Francis visits Cuba Cuban President Raul Castro walks with the Pope after his arrival on September 19. Hide Caption 22 of 23 Photos: Pope Francis visits Cuba Pope Francis' cap flies off his head as he deplanes in Havana on September 19. Hide Caption 23 of 23

Wuerl: I hear from so many young adults that they find in the Holy Father a reason to re-evaluate their religious lives, that they are starting to go to Mass again and reconnecting with the church. So, I'm quite excited about the impact of his visit. The Pope's 'cherry on the cake'

In his last stop in Cuba, Pope Francis met with families at Our Lady of the Assumption Cathedral in Santiago. He called the event the "cherry on the cake" and spoke about the importance of families.

Francis said there's no perfect family, and it's OK for families to disagree. He said he's "more afraid of those who say, 'We never argue.'"

Before heading to the airport, Francis offered up a blessing of the bellies. He asked all pregnant women to rub their bellies while he wished their unborn children good health.

Pope soft on communism?

During his trip to Cuba, Pope Francis took a few subtle jabs at the country's communist leadership. But he hasn't gone far enough for some American conservatives.

Soon after landing, the Pope invoked a Cuban hero to criticize political dynasties , a remark that many interpreted as referring to the country's presidents for the last six decades, Raul and Fidel Castro. He also called for Catholics to be allowed more religious freedom.

Some observers say Pope Francis's views on poverty and wealth make him a communist - is he? 📻 http://t.co/gvTOCxA9QX pic.twitter.com/la4LIv2seS — BBC World Service (@bbcworldservice) September 20, 2015

During his trip to Cuba in 1998, St. John Paul II called for "great change" and urged greater respect for religious and other human rights, Thavis said. Pope Benedict XVI echoed that call in 2012.

Aboard the papal airplane on the way to Cuba, Benedict said , "It is obvious that the Marxist ideology as it was conceived no longer corresponds to reality: It is no longer possible to respond to or to build up a society in this way. New models must be found, patiently and constructively."

Despite his frequent critiques of capitalism, Pope Francis says he is no Marxist. "Marxist ideology is wrong," he told an Italian newspaper in 2013

Thavis notes that the Pope could be critiquing communism behind the scenes in Cuba, in his meetings with Raul Castro.

But it will be interesting to watch whether Francis -- who is rarely shy about sharing his political opinions -- will say anything to the Cuban people about the system they've endured since 1959.

My prayer for this week: that Pope Francis embraces Capitalism. It's a long shot, but if he really wants to alleviate poverty, he will. — Joe Walsh (@WalshFreedom) September 21, 2015

No meeting with dissidents

At a briefing on Monday, Vatican spokesman the Rev. Federico Lombardi took a question about whether the Pope would meet with dissidents before leaving Cuba.

"It's true that there were telephone calls from some people in the Nunciature, but there was no scheduled meeting, in the full sense of a one-on-one kind of talk," he said.

Father Lombardi on #popefrancis meeting with dissidents.... Some calls were made from nunciature. https://t.co/DrXiQahjpU — Rosa Flores (@RosaFlores) September 21, 2015

The Pope goes off script

Pope Francis wrapped up his weekend by going off script at two events in Havana on Sunday. During evening vespers, he called on society to protect the "smallest" and most vulnerable, including the unborn.

Speaking spontaneously to a group of Cuban nuns, priests, seminarians and bishops, Francis said that "Jesus shines" in the lives of "hidden" and "ignored" people, such as those who suffer from degenerative diseases.

Francis also referred to prenatal testing that can "forecast" illnesses in the womb, leading some parents to "return it before it comes into the world."

The Pope said he wanted to speak off the cuff in response to two "prophets" who spoke before him Sunday evening. One was a nun who works with severely ill children.

Repeating a familiar theme, Francis also called for the church to embrace a "spirit of poverty," saying that "wealth takes away the best of us."

Later Sunday evening, under a drizzle of rain, Francis urged a crowd of Cuban youth in Havana to "open yourself and dream."

"Dream that if you give the best of yourself, you'll help make the world a different place."

While avoiding overtly political statements, Francis also repeated his frequent criticism of a "throwaway culture" and the "idolatry of money."

Meeting with Fidel Castro

Francis followed up the Mass on Sunday with a private meeting with former Cuban President Fidel Castro, the Vatican said.

The two met in Castro's Havana residence and were joined by members of Castro's family.

Francis and Castro exchanged books during what Lombardi described as a "friendly and informal" meeting.

Pope Francis and Fidel Castro greet each other in Havana on Sunday.

Castro presented Francis with the interview book "Fidel & Religion." He wrote inside, "For Pope Francis, on occasion of his visit to Cuba, with the admiration and respect of the Cuban people."

Before hanging out with Castro, the Pope made his way through Havana in an open popemobile. He was greeted by throngs of cheering Catholics.

Francis told those gathered at the Mass to pay attention to the call to serve and care for those who are the most vulnerable.

A return to prayer for Raul Castro?

Cuban President Raul Castro -- an atheist -- was among those in attendance at the Mass. After meeting with Francis at the Vatican in July, Castro said, "If the Pope continues talking like this, I may return to the church and start praying again."

JUST WATCHED Cuban President returning to the church? Replay More Videos ... MUST WATCH Cuban President returning to the church? 02:27

The Pope's secret diplomacy

In addition to having an impact on Castro's views of the church, the Pope also played a key role in the thawing of U.S.-Cuba relations.

In fact, Francis has long been encouraging the U.S. and Cuba to play nice.

In an exclusive interview, Havana's archbishop, Cardinal Jaime Ortega y Alamino, revealed to CNN that when the Pope and U.S. President Barack Obama met at the Vatican for the first time in March 2014, the Pope lobbied Obama to lift sanctions on Cuba.

JUST WATCHED Pope Francis heads to Cuba after months of secret diplomacy Replay More Videos ... MUST WATCH Pope Francis heads to Cuba after months of secret diplomacy 02:50

Francis pressed leaders to go even further when he landed in Havana on Saturday, calling on the communist nation to "open itself to the world."

The Catholic Church was once an integral part of Cuban history, the Pope said, inspiring veterans of its war for independence and "sustaining the hope which preserves people's dignity in the most difficult situations."

In his short speech, Francis also invoked Jose Marti, a Cuban hero, to deliver a veiled critique of the Castros, said Andrew Chesnut, a professor of Latin American history at Virginia Commonwealth University. Marti, a George Washington-type figure, died in 1895 during the war for independence

But not everyone is impressed with the Pope's efforts to deepen U.S. diplomatic ties with Cuba.

"I just think the Pope is wrong," New Jersey Gov. Chris Christie and Republican presidential candidate said Sunday in an interview with CNN's Jake Tapper on "State of the Union."

JUST WATCHED Gov. Chris Christie on State of the Union: Full interview Replay More Videos ... MUST WATCH Gov. Chris Christie on State of the Union: Full interview 07:38

"The fact is that his infallibility is on religious matters, not on political ones," said Christie, who is Catholic.

A mix of religions

In Cuba, many people say they are both Catholics and Santeros.

CNN's Patrick Oppmann takes a look at Santeria, a religion that has its roots in Cuba's slave trade. The slaves who were brought to Cuba from Africa were forced to convert to Christianity. But Catholicism mixed with African traditions, and Santeria was born.

JUST WATCHED The rise of Santeria in Cuba Replay More Videos ... MUST WATCH The rise of Santeria in Cuba 02:44

Aboard the papal plane

The Pope arrived in Cuba on Saturday afternoon, following a lengthy flight from Rome. CNN's Rosa Flores has been on the papal plane with Francis, and had a chance to speak with him there.

One of the most memorable moments of my life! #popefrancis offers me his blessing on the #papalplane More on @CNN pic.twitter.com/COsnVLPxrV — Rosa Flores (@RosaFlores) September 19, 2015

She's been sharing her unique view of the trip (and plane) on social media.