Instead, Ebrard said during a press conference in Mexico City Monday, if the deal announced Friday does not begin to drive down migrant numbers in the next 45 days, officials will open up new discussions in which the U.S. will again push for the safe third country measure and Mexico will propose establishing a regional refuge system in conjunction with the United Nations and the governments of Guatemala, Panama and Brazil — three countries that are often starting points for migrants headed to the U.S.