Mr. Magnus, the police chief in Tucson, Ariz., will seek to win the trust of the U.S. Border Patrol, an agency championed by former President Donald J. Trump.
The Biden administration is fighting to preserve Title 42, a public health rule that turns back families at the border during the pandemic. But some have been allowed to stay in the United States, despite the rule.
A judge had ordered the Biden administration to restart the Trump-era program, but doing so required cooperation from Mexico, which had been reluctant until now.
The reopening comes just ahead of the holiday season, clearing the way for tourists and other nonessential travelers after about 19 months of border closures
A court ordered the administration in August to reinstate the program, which forces some migrants to wait in Mexico while their asylum cases are pending.
After an inquiry into a private Facebook group where racist memes were shared, 60 employees were found to have violated the agency’s code of conduct. Two were fired.
More than 160 reports, obtained by Human Rights Watch, reveal details of mistreatment that asylum seekers described experiencing from border officials and while in U.S. custody.
Mr. Mayorkas had been vaccinated and was “experiencing only mild congestion,” a spokeswoman said. The infection was caught by routine testing ahead of a trip abroad.
The treatment of Haitians apprehended in Del Rio, Texas, has galvanized civil rights groups and others to press for change.
The change comes during a labor shortage in the United States, offering reassurance that undocumented workers are not at risk of being deported en masse.