Mr Obama heads first to Brazil, a major market for US goods, where he hopes to bolster ties with new Brazilian President Dilma Rousseff.

He later travels to Chile and El Salvador.

The White House bills the trip as a way to create US jobs by deepening economic ties with Latin American countries.

Brazilian authorities have raised security for Mr Obama's visit and police in Rio had closed a number of streets in preparation.

Police fired rubber bullets and tear gas to break up a demonstration of about 300 people protesting against the US at the US consulate in Rio on Friday.