Obama Hosts Pope at White HousePresident Barack Obama welcomed Pope Francis to the White House Wednesday with an official arrival ceremony on the South Lawn and an estimated 15,000 people in attendance. Francis' first full day in the United States Wednesday will be spent meeting with Obama, addressing the U.S. bishops and canonizing an 18th-century Spanish missionary who spread the word of the church in what is now California. "I believe the excitement around your visit must be attributed not only to your role as pope, but to your unique qualities as a person. In your humility, your embrace of simplicity, the gentleness of your words and the generosity of your spirit," Obama said in welcoming the pope. "You call on all of us, Catholic and non-Catholic alike, to put the “least of these” at the center of our concern," the president continued. "You remind us that in the eyes of God our measure as individuals, and as societies, is not determined by wealth or power or station or celebrity, but by how well we hew to Scripture’s call to lift up the poor and the marginalized, to stand up for justice and against inequality, and to ensure that every human being is able to live in dignity – because we are all made in the image of God," he said. In his speech, Obama referenced refugees fleeing war-torn lands, religious liberty and the "sacred obligation to protect our planet," and thanked the pope for his efforts in bettering relations between the U.S. and Cuba. After Obama and the pope make brief remarks, the leaders will head into the Oval Office for one-on-one talks that administration officials said will be centered not on advancing a political agenda, but on committing to shared values. “The way that both of these men have dedicated their lives to advancing values related to social justice and prioritizing those who are less fortunate and that they pursue those values with a sense of conviction, I think, gives them a lot of things to talk about,” White House Press Secretary Josh Earnest told reporters Tuesday. In addition to combating social and economic inequality, White House officials point to other areas of common ground including the fight against climate change – the focus of Pope Francis’ encyclical that came just months before a United Nations climate conference in Paris in December. “I think the pope has spoken about the need for all of us to meet our responsibility to care for God’s creation. And that I think provides an important moral backdrop to the type of policy decisions that individual leaders will make on climate change,” Deputy National Security Adviser Ben Rhodes said in a recent press call. Some conservatives have criticized Francis' economic views, calling them Marxist. The pope defended himself, telling reporters on his flight to the U.S. from Cuba Tuesday that some people may have an inaccurate impression that he is "a little bit more left-leaning." "I am certain that I have never said anything beyond what is in the social doctrine of the church,'' he said. "It is I who follow the Church ... my doctrine on all this ... on economic imperialism, is that of the social doctrine of the Church." Other topics Pope Francis has also spoken out against the persecution of religious minorities – particularly in the Middle East, where Islamic State militants have targeted Christians and Yazidis in deadly attacks. This commitment to religious liberty and the rights of religious minorities is another shared value, White House officials said. Other possible topics of discussion – immigration, the Iran nuclear agreement and the normalization of ties between the United States and Cuba – an area where administration officials say the pope’s leadership in promoting engagement was critical. While Obama and the pope share common ground, they differ sharply on other issues, such as abortion and same-sex marriage. After his meeting with Obama Wednesday, Francis will take part in a parade around the National Mall, hold a prayer meeting with U.S. bishops, and celebrate a Mass canonizing Junipero Serra, the Franciscan friar who founded Catholic missions along the coast of California while marching with Spanish conquistadors. Tens of thousands of people are expected to pack the streets around the Washington Monument and National Mall for the parade after the White House meeting. Before departing for the White House Wednesday morning, Pope Francis stopped to talk to people gathered outside the Apostolic Nunciature, the Vatican's Embassy, where he is staying while in Washington. Thousands were invited to participate in the welcoming ceremony on the White House's South Lawn Wednesday. Christina Toth from Boyds, Maryland, said, "I feel like this is a pope for the people. He stands for all of humanity and power and he seems very approachable. We haven't seen that in a pope before." Toth said she is a Catholic, "more so now than any other time in my life," due to Francis' papacy. Ben Paracchio of Asheville, North Carolina, said, "This is a historic moment. I'm really fortunate that I get to be here. I really admire this pope and all that he stands for." Native Americans Serra's elevation to sainthood is a sore point for many Native Americans, who say Serra contributed to the abuse and elimination of many indigenous tribes from enslavement and disease. The pope arrived in the United States Tuesday after a historic visit to Cuba and the Vatican hosted U.S. and Cuban delegations last December as both sides finalized an agreement. “Not only was the church an institution that was very important to large amounts of people in both Cuba and the United States, but Pope Francis was uniquely respected in both Cuba and the United States, which made both him and the Vatican exactly the right supporters for the process of normalization,” Rhodes said. “And that gave good impetus for our efforts.” When the pope's plane touched down at an airbase outside of Washington Tuesday, Obama, Vice President Joe Biden and their respective families were all on hand to personally greet him. It was an unprecedented welcome for an unprecedented visit. “Our goal here has been to ensure that the way the pope is received here in the United States is consistent with the warm feelings of admiration and respect that the American people have for the pope, his teachings, his values and the way he has lived in life,” White House spokesman Earnest said. Amid cheers of “welcome to the U.S.A.,” the pope disembarked from the plane, shaking hands with the first and second families, local archbishops and Catholic students, as he began his historic trip to the United States. Apostolic Nunciature After the greeting from Obama and hundreds of cheering well-wishers, Francis was taken by motorcade to the Vatican's diplomatic mission, the Apostolic Nunciature, where he will stay during his visit to the nation's capital. Instead of a luxury limousine, the 78-year-old pope rode in a simple black Fiat sedan, waving to the large enthusiastic crowds that lined the route to the mission. Obama last met with the pontiff at the Vatican in March of 2014 – but it is the first time the pontiff has set foot on American soil. Trip details On Thursday, Francis becomes the first-ever pope to deliver an address before a joint meeting of Congress. He will travel to New York City Friday to address the United Nations General Assembly. On Saturday morning, he'll travel to Philadelphia for this weekend’s Vatican-sponsored World Meeting of Families. On Sunday, he will celebrate an outdoor Mass, which is expected to draw about 2 million people. Richard Green contributed to this report. Some material for this report came from Reuters and AP.