WASHINGTON — The Obama administration will soon expand efforts to help Central American families and children legally immigrate to the United States amid another surge of migrants caught crossing the border illegally. White House Deputy Homeland Security Adviser Amy Pope said Tuesday that the administration will expand in-country refugee processing for families coming from Honduras, El Salvador and Guatemala and launch an effort to temporarily relocate some families to Costa Rica. The government is also broadening a nearly two-year-old program to allow some Central American children to reunite with parents already legally living in the United States. Deputy Homeland Security Secretary Alejandro Mayorkas said that program will now allow some unmarried siblings, in-country parents and other caregivers to move to the U.S.