Josefina Vidal, head of the Cuban foreign ministry's U.S. division, arrives for a press conference after the second round of talks between Washington and Havana to re-establish diplomatic relations, in Washington D.C., capital of the United States, on Feb. 27, 2015. Roberta Jacobson, U.S. Assistant Secretary for Western Hemisphere, said Friday she is optimistic that the U.S. and Cuba could open embassies before the Summit of the Americas slated for April 10-11. (Xinhua/Bao Dandan)