Fidel Castro says Obama's smile can't be trusted

Cuba's President Fidel Castro addresses the audience during a political rally in celebration of the 12th birthday of Cuban boy Elian Gonzalez in Cardenas December 6, 2005.

HAVANA (Reuters) - Former Cuban leader Fidel Castro warned on Monday that President Barack Obama's "kindly smile" could not be trusted, saying Washington was plotting against leftist Latin American governments including Venezuela's.

Castro, 83, who ran Cuba for nearly 50 years before poor health led him to hand the presidency to his younger brother Raul last year, initially welcomed Obama's election but has been increasingly critical.

In a letter read by Venezuelan President Hugo Chavez at a gathering of leftist leaders in Havana, Castro said the United States was backing rightist movements in a bid to weaken Chavez and other regional socialist leaders.

"The empire's real intentions are obvious, this time beneath the kindly smile and African American face of Barack Obama," Castro's letter said.

"The empire is mobilizing behind rightist forces in Latin America to strike Venezuela and, in doing so, strike (other leftist) states," the letter said.

Castro, who came to power at the head of the 1959 Cuban revolution, criticized Washington's stance on a June 28 coup in Honduras and a deal to allow U.S. troops more access to Colombian military bases.

The elder Castro has been seen only in occasional photos and videos since having surgery for an undisclosed intestinal ailment in July 2006. He still has a behind-the-scenes role in government and keeps a high profile through his writings.

Last week, he chided Obama for accepting the 2009 Nobel Peace Prize as he steps up the U.S. war effort in Afghanistan by deploying more troops.

Chavez, Washington's most outspoken critic in Latin America, called Obama "the Nobel War Prize" winner on Monday.

(Reporting by Helen Popper and Rosa Tania Valdes; Editing by Bill Trott)