The Globe and Mail Doina Chiacu Bookmark Please log in to listen to this story. Also available in French and Mandarin. Log In Create Free Account Getting audio file ... This translation has been automatically generated and has not been verified for accuracy. Full Disclaimer Andrew Harnik/The Associated Press The United States is facing the biggest surge of migrants at its southwestern border in 20 years, the homeland security secretary said on Tuesday as the Biden administration races to handle an influx of children trying to cross the U.S.-Mexico border alone. The number of attempted border crossings by people from Central America and Mexico has steadily increased since April 2020 and most single adults and families are being turned away, Homeland Security Secretary Alejandro Mayorkas said.