The Trump administration launched an immigration enforcement blitz nationwide Sunday that included multiple federal agencies and resulted in the arrest of nearly 1,000 people, according to Immigration and Customs Enforcement.

Trump wasted little time in pushing forward his immigration plans. Within hours of taking the oath of office Monday, he signed a flurry of executive orders that closed the U.S. to refugees, cracked down on undocumented immigrants with criminal backgrounds and challenged what it means to be “American.

President Donald Trump issued a flurry of executive orders and edicts on immigration and enforcement in the first days of his new administration, seeking to counter what he called “a large-scale invasion at an unprecedented level.