Ambassador Liliana Ayalde is a career diplomat with three decades of experience and a former ambassador to Paraguay. She most recently served as the deputy assistant secretary of state for Western Hemisphere affairs, covering Cuba, Central America and the Caribbean.
Tensions between Brazil and the U.S. have hiked since media reports emerged about a National Security Agency spy program targeting Brazil.
Those reports were based on leaked NSA documents and indicate that President Dilma Rousseff's communications were intercepted. They also show the NSA targeted the private computer network of the state-run oil company Petrobras.
Ayalde succeeds Thomas Shannon, who is now a counselor to Secretary of State John Kerry.
Copyright 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.