Houston, July 19 -- The U.S. government on Friday expanded its policy requiring asylum seekers to wait outside the country to one of Mexico's most dangerous cities, where thousands of people are already camped, some for several months.

The Department of Homeland Security said Friday that it would implement its Migrant Protection Protocols in Brownsville, Texas, across the border from Matamoros, Mexico. DHS says it anticipates the first asylum seekers will be sent back to Mexico starting Friday.

Under the so-called "Remain in Mexico" policy, asylum seekers are briefly processed and given a date to return for an immigration court hearing before being sent back across the southern border. Since January, the policy has been implemented at s...