WASHINGTON - Pope Francis, in one of his most politically charged speeches of his American trip, on Wednesday morning encouraged U.S. bishops to stand strong against "the challenging issues of our time," including immigration, abortion, climate change and accusations of child sex abuse by Catholic priests.

"The future freedom and dignity of our societies depends on how we face these challenges," Francis told the gathering of about 300 bishops at the Cathedral of St. Matthew the Apostle in Washington, D.C., according to the official English translation of his Italian remarks. "The innocent victim of abortion, children who die of hunger or from bombings, immigrants who drown in search for a better tomorrow, the elderly or the sick who are considered a burden, the victims of terrorism, wars, violence and drug trafficking, the environment devastated by man's predator with nature-at stake in all of this if the gift of God, of which we are noble stewards but not masters."

Saying that he had not come to "judge ... or to lecture" the Catholic leaders, Francis said a key purpose of his "apostolic mission" was to offer support and guidance. He urged the bishops to deal with challenges facing the church with "dialogue" and not anger.

"Harsh and divisive language does not befit the tongue of a pastor, it has no place in his heart," Francis said. "Although it may momentarily seem to win the day, only the enduring allure of goodness and love remains truly convincing."

Francis said he appreciated the "unfailing commitment of the Church in America to the cause of life," but also reiterated his message of inclusion, saying no American should feel "excluded from the pope's embrace."

"It is not about preaching complicated doctrines, but joyfully proclaiming Christ who died and rose for our sake," he said.

Appearing to address sex scandals that have plagued the Catholic Church, Francis said he was conscious of "the courage with which you have faced difficult moments in the recent history of the Church in this country."

"I realize how much the pain of recent years has weighed upon you and I have supported your generous commitment to bring healing to victims - in the knowledge that in healing we too are healed- and to work to ensure that such crimes will never be repeated." The bishops erupted in applause.

Concluding his remarks, the pope offered two recommendations he said were "close to my heart." First, he urged the bishops to support priests, find ways to encourage their spiritual growth, and "not let them be content with half-measures."

Second, he encouraged the bishops to open their hearts, and the church, to immigrants, particularly those from Latin America.

Joking that he may be "pleading my own case," the Argentinian pope, making his first visit to the United States, said although they might be "challenged by their diversity," the bishops should try to look into the souls of the immigrants and realize that they have "resources meant to be shared."

"So do not be afraid to welcome them," Francis said. "Offer them the warmth of the love of Christ and you will unlock the mystery of their heart."

The bishops gave Francis a standing ovation after his remarks. Many approached the pontiff, kissing his hand and greeting him, and according to his interpreter, the pope said he wished he could meet individually with all the bishops in attendance.

The bishops surprised the pope with two gifts. The first was an original painting depicting the saints that were born or served in the United States. The second was a monetary gift meant to help fund his charity work.

The pope arrived at the church shortly before noon, after a motorcade through the streets of the nation's capital and was greeted by the church's director. Upon entering the cathedral at 11:49 a.m., he sprinkled holy water at the entryway with an aspergillum. After accepting a gift of flowers, Francis slipped away to the back of the church to prepare for the ceremony.

He prayed quietly at the front of the church before taking his seat at the center of the altar for the beginning of the ceremony. After listening to a reading of the First Epistle of St. Peter, a microphone was brought to the pontiff and he led the gathering in prayer.

After Archbishop Joseph E. Kurtz, president of the U.S. Conference of Catholic Bishops, thanked the pope for "energizing" the church, Francis stood to address the cathedral. Speaking in Italian, he first offered his blessings for Jews observing Yom Kippur, or Day of Atonement, before launching into prepared remarks.

Earlier, throngs of Catholic worshippers gathered on the streets of the nation's capital Wednesday to get a glimpse of Francis in the first full day of his historic United States visit.

A group of Catholic faithful from the Archdiocese of Miami were on the Ellipse at 5 a.m. and grabbed spots on the first row behind the metal barriers, and were richly rewarded.

"We got the blessing right in front of us" from the pope, said Zully Maya. "We were waiting and got the blessing."

A friend, Mercy Allen, of Fort Lauderdale, said "it was emotional," adding that she did not expect that feeling, "but I feel good."

Another member of the Miami Archdiocese, Ines Bueno, said, "The Holy Spirit was coming to us."

Bueno praised Francis for raising the plight of immigrants. "He's coming to be the voice of a lot of those who have no voice here."

With police motorcycles leading the way, Francis cruised along Constitution Avenue standing atop a white Jeep Wrangler converted into the popemobile.

Though covered in bulletproof glass in the front, Francis leaned over the open driver's side, stopping to kiss a young girl wearing a red-patterned dress seconds into the parade along the route lined with U.S. and Vatican flags.

Flanked by about a dozen Secret Service agents -- some of them keeping a hand on the popemobile at all times -- a smiling Francis squinted under the bright sun and waved in all directions at the screaming gatherers, kept behind steel barricades.

The popemobile stopped again as a little girl dressed in pink approached the pope and gave him a gift.

It lasted only a few moments, but the pope's arrival along the Ellipse -- where thousands had gathered since before dawn -- caused a frenzy. People stood on railings of the metal barriers, all trying to get pictures of the pope as his popemobile went by.

Former Long Islander Pam Farrell, who used to live in Seaford and was among a group of four filing out of the parade area, was overjoyed having caught a glimpse of the pope.

"It was a once-in-a-lifetime experience, said Farrell, a Catholic who now lives in Olney, Maryland. "I feel really blessed."

Another of the quartet, Irene Cunningham of Brookville, Maryland, said emphatically: "A fabulous day. Glorious, blessed day!"

Eithne Ellis agreed, adding, "We're so glad we came."

Diana Zottman, an attorney from Seattle, who came to D.C. just to see Francis, said, "It's worth it." She wasn't sure she had captured a picture of Francis and had to brave being squeezed by the crowd pressing forward, but she said she wouldn't trade the experience.

"It was exciting, but too short," she said. "And a test of human survival."

Zottman added, "I've never done anything like this before." She said she came alone, after family members declined to join her.

A Catholic, Zottman said of Francis: "It's worth it. You can feel everybody here. It's unifying, said Zottman, who has a ticket to watch the pope's address to Congress from the Capitol lawn.

"It's euphoria. That's what it feels like," said John Brewer, a Catholic IT worker from Alexandria, Virginia, who was scrunched next to Zottman. "He really represents hope," Brewer said.

And Zottman said she also liked that many non-Catholics are excited about the pope and his message.

Sean Khoo, 18, noted how brief the glimpse of Francis was. "It was still pretty good."

Before the pope arrived along the parade route, Cecilia Khoo of Rockville, Maryland, put her book away and stood.

"I've never been in proximity to a pope before," she said, explaining why she came to the parade route.

"I'm a Catholic myself," said Khoo, a native of Singapore. "I'm here to honor my God. He's a man ... N> But he's an instrument of God. He speaks of peace and unity. I think that's important for the world."

A hush went over the thousands on the mall as Obama welcomed Pope Francis on the sun-dappled South Lawn of the White House, which people followed on the JumboTron.

The throng cheered when Obama noted with a smile, "I should explain that our backyard is not typically this crowded."

The cheers were even louder when the president said the crowds turning out to see the pope were a sign of the "deep devotion of some 70 million American Catholics."

When Francis, in his remarks, said he was a son of immigrants, a huge cheer went up among the thousands awaiting the papal parade along the Ellipse and the mall. That procession kicked off about 11 a.m., after a private Oval Office meeting between Francis and the president.

They came before sunrise, hundreds walking along the capital city's dark streets with a single purpose: to get a spot along the Ellipse on Constitution Avenue to view Pope Francis.

A Catholic family from Charlotte, North Carolina, John and Jacquie Stevens and their four children, were relaxing on blankets about 25 feet from the closet vantage point adjacent to the street.

"Not bad," Jacquie Stevens said of her family's spot. They were surprised, though, that so many people were on hand so early.

Through their church parish at home, Jacquie Stevens said they got tickets to watch the pope's address to Congress outside on Capitol grounds.

"It's pretty big," she said, especially for the children, who are ages 12, 10, 8 and 6.

Jacquie Stevens said Francis is "just a pope for everybody. He draws everybody, even if you're not Catholic. He welcomes everybody."

With the Washington Monument looming in the background, multitudes of people waited in line to get screened at metal detectors.

Instructions were called out by screeners. No folding chairs; take everything out of your pockets; no food or drink allowed. A haphazard collection of food stuffs, half-eaten apples, bananas and soft drink bottles was piling up.

Law enforcement arrayed at intervals were patrolling, some with dogs.

Despite the security precautions, the crowd was ebullient -- even hours before Francis would make an appearance.

Much like the scene Tuesday afternoon outside the Apostolic Nunciature when the pope arrived in D.C., there was singing and dancing as the sun rose Wednesday morning.

Television reports said people had started to gather in the area at midnight, even though security gates did not open until 4 a.m. for the unticketed event.

Amanda Possoby, 36, of Annapolis, Maryland, came with a friend to the Ellipse for the papal parade, in honor of her late father, Michael Possoby Jr.

"I lost my dad five years ago," Possoby said. "He was a devout Catholic. I'm doing this in honor of him."

Like the thousands who lined Constitution Avenue, she was hours early for the parade.

As someone who grew up Catholic but has since fallen away from the faith, Possoby said, Francis was "starting to inspire me" to return to practicing Catholicism. She said Francis represented "unity, peace and I would also say love."

Her friend, Tony Teano, also from Annapolis, said Francis inspired many hopes for change that Teano would like to see in the church.

"I believe that Pope Francis represents significant change and a shift in the tone of the papacy," he said.

Teano said he was raised Catholic but left the church when he was told, "I would go to hell for being gay."

"I'm here out of hope that the church grow and change and embrace everybody in increased love," Teano said. That, he said, is the way to embody the teachings of Christ.