This bill would direct the Secretary of Homeland Security to immediately stop all immigration processing functions at southern border ports of entry and instead detain and remove all aliens apprehended there. The cessation of these immigration functions would continue until the Secretary certifies to Congress that no individuals on the terrorist screening database can enter the United States at any point along the southern border, at which point the closure would end 15 days later. The bill affects immigration officials and all individuals seeking to enter the United States at the southern border, as well as those apprehended crossing unlawfully. The legislation requires the Department of Homeland Security to submit a report to Congress identifying security risks and capability gaps along the border and outlining plans to screen all apprehended individuals against the terrorist screening database. No specific funding levels or appropriations are included in the bill text provided.