In recent weeks, there’s been an uptick in the number of attempted border crossings between Mexico and the United States. With new US President Joe Biden seen as more welcoming, migrants are trying their luck, while others are sent back for sanitary reasons. More than 100,000 of them were arrested near the US border in February. Ciudad Juárez, a border city in Mexico, has become a de facto migrant expulsion centre and is struggling to cope, especially as some aid facilities have closed or limited their capacity due to the Covid-19 pandemic. Our correspondents report.