In slow dance with capitalism, Cuba's Communists turn to future

Cuban President Raul Castro gestures to the audience while waiting for U.S. President Barack Obama to make a speech to the Cuban people, in the Gran Teatro de la Habana Alicia Alonso in Havana, March 22, 2016. REUTERS/Stringer

HAVANA (Reuters) - President Raul Castro warned Cubans on Saturday that the United States was determined to end Cuba's socialist revolution despite restoring relations and a visit by U.S. President Barack Obama, saying one-party Communism was essential to defend the system.

"We must be alert, today more than ever," Castro said, speaking in front of a giant portrait of his brother Fidel Castro at the inauguration of the Communist Party's first congress in five years.