Speaking in the birthplace of the US, Pope Francis has offered stout words of support to Hispanic and other immigrants in the country, telling them not to be discouraged at a time when some prominent politicians are directing hostility toward them.

The 78-year-old Argentine pontiff toured Independence Hall in Philadelphia before addressing a crowd estimated at more than 40,000 outside the 18th century red brick building where basic US liberties were proclaimed and where independence from Britain was declared.

"Do not be discouraged by whatever challenges and hardships you face," the pope told the many Hispanics and other recent immigrants in the crowd on Saturday, adding that he felt "particular affection" toward them.

During his first visit to the country, the leader of the world's 1.2 billion Roman Catholics on Thursday had urged Americans in a historic speech to Congress to reject "a mindset of hostility" toward immigrants.

He expanded on that issue in his Philadelphia speech, delivered in Spanish.

The pope said immigrants "bring many gifts" to their new nation.

"You should never be ashamed of your traditions," he said to a round of applause. "I repeat, do not be ashamed of what is part of you."

The pontiff noted that US history includes ending slavery in the 1860s and "the gradual effort to eliminate every kind of racism and prejudice directed at successive waves of new Americans".

"Remembrance saves a people's soul from whatever or whoever would attempt to dominate it or use it for their interests," he said.

Harsh rhetoric

Harsh rhetoric toward "illegal" immigrants has featured heavily in the race for the Republican nomination for the November 2016 US presidential election.

Republican frontrunner Donald Trump has called for deporting all 11 million illegal immigrants, most of whom are from Latin America like the pope, and has accused Mexico of sending rapists and other criminals across the border.

He and many other Republicans also are calling for the construction of a wall along the US-Mexico border.

Philadelphia Mayor Michael Nutter told the crowd before the pope's speech" "We are all immigrants. Whether we arrived 10 generations ago or 10 minutes ago, we cannot let the xenophobia and racism of some to carry the day."

The pope spoke from the lectern used by President Abraham Lincoln for his famed 1863 Gettysburg Address after the bloodiest battle of the US Civil War that declared that "government of the people, by the people, for the people, shall not perish from the Earth."

In unscripted remarks on a separate subject, the pope also said globalisation is good if it does not destroy the riches and distinctiveness of peoples. He said real globalisation must respect different cultures equally.

"You could see he was very, very moved," New York's Cardinal Timothy Dolan told reporters. "And he said 'You know, Buenos Aires was a city of immigrants too,'" Dolan said.

Francis, the first Latin American pope, has taken up the plight of immigrants a main issue of his papacy, along with climate change, economic equality and religious freedom.

Source: Reuters