US Secretary of State Condoleezza Rice. AFP PHOTO

Her message was broadcast on TV Marti, a service sponsored and financed by the US government, The New York Times reported.

"The United States respects your aspirations as sovereign citizens," Rice said. "And we will stand with you to secure your rights -- to speak as you choose, to think as you please, to worship as you wish and to choose your leaders, freely and fairly, in democratic elections."

Fidel Castro, who has ruled Cuba for 47 years, handed over power temporarily to his brother Raul this week because of health problems. Neither brother has appeared in public in recent days, although official announcements say that Fidel Castro is making a good recovery after surgery.