A temporary U.S. immigration ban against three African nations is a concern for the entire continent, the outgoing head of the African Union commission said Monday as dozens of African leaders met for an annual summit. In Africa the ban targets Libya, Somalia, Sudan, predominantly Muslim nations with already complicated, sometimes strained, relations with the United States. The U.S. government does not maintain an embassy in either Libya or Somalia, largely because of safety concerns. But in a speech before dozens of African leaders at the opening of the African Union summit on Monday, commission chairwoman...