The Trump administration on Friday will start forcing some asylum seekers to wait in Mexico while their cases wind through U.S. courts, an official said, launching what could become one of the more significant changes to the immigration system in years.

Pope Francis said Wednesday that fear of migration is "making us crazy" as he began a trip to Central America amid a standoff over President Donald Trump's promised wall at the U.S.-Mexico border and a new caravan of migrants heading north.

Most of the undocumented immigrants who are in the United States have overstayed a visa and did not cross the border illegally, according to a new analysis from the Center of Migration Studies.

In cities across the country, local activists marched in support of a progressive agenda centered on economic justice, racial justice and immigrant rights.

“We will just do what we need to do to help people in need,” said Antonio Fernandez, C.E.O. of Catholic Charities for the Archdiocese of San Antonio.