Street vendors sell food wearing face masks as a preventive measure to avoid the spread of COVID-19 coronavirus, at San Ysidro crossing in Tijuana, Baja California state, Mexico, on April 23, 2020, on the US-Mexico border. - US President Donald Trump partially blocked immigration to the United States "to protect American workers" from the economic shock of the coronavirus, as the United Nations warned the world was facing "a humanitarian catastrophe". (Photo by Guillermo Arias / AFP) (Photo by GUILLERMO ARIAS/AFP via Getty Images)