Brazil, Mexico ask U.S. to explain if NSA spied on presidents

Brazil's President Dilma Rousseff participates in the inaugural ceremony for the new Minister of Foreign Affairs of Brazil Luiz Alberto Figueiredo Machado at the Planalto PalaceBy Anthony Boadle BRASILIA (Reuters) – Brazil assailed the United States on Monday after new allegations that Washington spied on President Dilma Rousseff, complaining that its sovereignty may have been violated and suggesting that it could call off Rousseff's planned state visit to the White House next month. A Brazilian news program reported on Sunday that the U.S. National Security Agency spied on emails, phone calls and text messages of Rousseff and Mexican President Enrique Pena Nieto, a disclosure that could strain Washington's relations with Latin America's two biggest nations. …