Pope Francis met for lunch with 200 people who are homeless or living in poverty in Washington on Thursday and told them there was no social or moral justification for homelessness.

Francis, after delivering a speech to the U.S. Congress in which he urged lawmakers to do more to help society's most vulnerable people, visited a Catholic Charities center that provides food, medical services and help in job hunting.

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"We can find no social or moral justification, no justification whatsoever, for lack of housing," the pope told charity workers, donors and recipients in the capital of the world's richest country.

Francis has made advocacy for the poor a center point of his tenure, born out of his time spent in slums and soup kitchens as a church leader in Argentina before becoming pope in 2013, the first from Latin America.

As the first pope to speak before the U.S. Congress, he told lawmakers to "keep in mind all those people around us who are trapped in a cycle of poverty. They too need to be given hope."

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Some of the people the pope met at the Catholic Charities center said they hoped his words would prompt Congress and other elected officials to do more to meet the needs of the poor.

"You never hear them speak about homelessness or how the job market has been. You hear the job market is bad, but you don't hear them say, 'What can we do to help?'" said Angela Ford, 45, who several years ago lost her job in the auto industry and lives in housing provided by the church.

"With all the negative political messages, it's great to have someone positive here."

The National Alliance to End Homelessness group said in a policy paper in April on homeless trends in 2013/14 that 578,424 people in the United States were sleeping outside, in an emergency shelter or temporary housing on a night in January 2014. It said that while the economy was recovering from the Great Recession in that period, overall homelessness decreased by 2.3 percent.

Eric Dyer, 50, who said he has faced bouts of homelessness since 1988 and is currently homeless, said he hoped the pope's call would help put pressure on Congress to do more to help the destitute.

"I think that they are so busy up there a lot of times that when they do get a chance to think about our situation, it just gets pushed under the table like bread crumbs," Dyer said as he waited to meet the pope. "There should be a system in place that doesn't allow them to do that."

The visit was likely intended to underline his remarks to Congress, said Rev. John Jenkins, president of the University of Notre Dame, a Catholic university.

"The wonderful thing about this pope is he does it in words, but even more powerfully, he does it in gestures," Jenkins said.

The pope blessed a meal of boneless teriyaki chicken breast and pasta salad for the group before mingling with the crowd, shaking hands and pausing for photos as admirers shouted in Spanish "Papa! Papa!" He recalled the biblical story of Jesus' birth, which starts with his parents being unable to find a place to stay in Bethlehem.

"The Son of God came into this world as a homeless person," Francis said. "The son of God knew what it was to start life without a roof over his head."