Data breaches at the U.S. government's personnel management agency by hackers, with suspicions centering on China, involved millions more people than previously estimated, U.S. officials said on Thursday.
President Barack Obama's national security adviser Susan Rice urged warring leaders in South Sudan on Thursday to end their conflict, blaming the nation's president, Salva Kiir, and rebel leader Riek Machar for "appalling crimes" and violence.
Russia is the biggest threat to U.S. national security and America must boost its military presence throughout Europe even as NATO allies face budget challenges and scale back spending, U.S. Air Force Secretary Deborah James said on Wednesday.