Pope Francis Joins Obama for Historic White House Address: 'We Are Living at a Critical Moment of History

Pope Francis joined President Barack Obama and his wife Michelle Obama at the White House on Wednesday morning for a welcome ceremony that included brief remarks from both leaders, with the pontiff focusing intently on addressing climate and environmental concerns.

"Mr. President, I find it encouraging that you are proposing an initiative for reducing air pollution," Pope Francis said from the South Lawn of the White House. "Accepting the urgency, it seems clear to me also that climate change is a problem which can no longer be left to a future generation. When it comes to the care of our common home, we are living at a critical moment of history."

President Barack Obama and Pope Francis speak at the White House (White House/YouTube)

The pope opened his speech with gratitude for Obama's warm welcome and by noting that he is the "son of an immigrant family."

"I'm happy to be a guest in this country, which was largely built by such families," the pontiff said. "I look forward to [these] days of encounter in which I hope to listen to and share many of the hopes and dreams of the American people."

Pope Francis went on to discuss religious freedom, and the need for U.S. bishops to defend it.

"With countless other people of good will, they are likewise concerned that efforts to build a just and wisely ordered society respect their deepest concerns and their right to religious liberty," Pope Francis said. "That freedom remains one of America’s most precious possessions. And, as my brothers, the United States bishops, have reminded us, all are called to be vigilant, precisely as good citizens, to preserve and defend that freedom from everything that would threaten or compromise it."

Pope speaks about religious liberty and individual rights. pic.twitter.com/RpyfaQEnMN

— Fred Lucas (@FredLucasWH) September 23, 2015

He specifically highlighted some of the activities that he'll partake in during his first trip to the U.S., including an address before Congress on Thursday morning, during which he said that he hopes "as a brother of this country to offer words of encouragement to those who guide the nation's political future in fidelity to its founding principles."

"It seems clear to me also that climate change is a problem [that] can no longer be left to future generations," he said. "When it comes to the care of our common home, we are living at a critical moment of history."

Pope: Climate change no longer a problem to be left to future generations. pic.twitter.com/4QjfKaPiqI

— Fred Lucas (@FredLucasWH) September 23, 2015

He also called for a protection of the "vulnerable in our world."

Throughout the pope's remarks, many in the crowd shouted, "Viva," and "We love you Pope Francis." The enthusiastic crowd roared as the band played "God Bless America," "Stars and Stripes Forever" and other patriotic tunes. Meanwhile, there was heavy security on the ground and security aircraft overhead, monitoring prohibited airspace.

The White House said that 11,000 tickets were issued, prompting Obama to joke, "Our backyard is not usually this crowded."

Obama took to the lectern before Pope Francis' remarks to welcome him to the United States, launching into his brief speech by proclaiming, "What a beautiful day the Lord has made."

The president proceeded to praise the Catholic Church, noting that he has seen the church's beneficial and positive work first-hand throughout his career working in poor neighborhoods and traveling as president.

U.S. President Barack Obama (R) guides Pope Francis (L) to his chair during his arrival ceremony at the White House on September 23, 2015 in Washington, DC. T(Win McNamee/Getty Images)

"I’ve seen firsthand how, every single day, Catholic communities, priests, nuns, and laity are feeding the hungry, healing the sick, sheltering the homeless, educating our children, and fortifying the faith that sustains so many," Obama said.

He also went on to praise Pope Francis for his humble attributes that have gained him accolades since becoming pontiff back in 2013.

"In your humility, your embrace of simplicity, the gentleness of your words and the generosity of your spirit, we see a living example of Jesus’ teachings, a leader whose moral authority comes not just through words but also through deeds," Obama said.

U.S. President Barack Obama and first Lady Michelle Obama welcome Pope Francis in an arrival ceremony at the White House on September 23, 2015 in Washington, DC. (Alex Wong/Getty Images)

The president also thanked the pontiff for supporting U.S. relations with Cuba, for reminding people of the "sacred obligation" to protect the planet, and for his support of individuals who wish to live their faith freely, proclaiming that the U.S. cherishes religious liberty.

"Here in the United States, we cherish religious liberty," Obama said. "Yet around the world at this very moment, children of God, including Christians, are targeted and even killed because of their faith."

After the public event on the South Lawn, Obama and Pope Francis walked past the Rose Garden on their way to a private meeting in the Oval Office, where Obama seemed to do most of the talking. Once the two were in the Oval Office, Obama commented on the accompanying media, "I notice that the pool is better behaved than usual."

Fred Lucas contributed to this post.