Cuban leader Fidel Castro called in to Venezuelan President Hugo Chavez's radio talk show on Tuesday, declaring he's "more energetic, stronger" and his country is running smoothly without him at the helm.

"I feel good and I'm happy," Castro said in a phone call to Chavez's weekday radio program. "I can't promise that I'll go over there soon, but, yes, I'm gaining ground."

Castro thanked Chavez for spreading news of his progress and complained that his supporters have "the habit, the vice of getting news daily."

"But I ask for patience, calm ... the country is marching along, which is what is important," Castro said in a soft but steady voice.

"And I ask for tranquility also for me so that I can fulfill my new tasks," he said.

During the half-year since Castro announced he had undergone intestinal surgery, the communist-led country has been governed by his brother Raul and a team of top leaders that includes Cuban Vice President and Cabinet Secretary Carlos Lage.

"You don't know how happy we are to hear your voice and know that you're well," Chavez said with obvious surprise in his voice at the unexpected call.

The two leaders, who are close friends and allies, spoke for almost 30 minutes.

Cuba's communist government has kept Castro's condition and exact ailment secret, and Chavez acknowledged that he has become an "emissary" for news of his health.

On Jan. 30, Havana's government released a new video of Castro looking stronger than in previous images as he met with Chavez, which quelled growing speculation that he was gravely ill.

The Cuban government has sought to reassure Cubans after intestinal surgery forced Castro to temporarily cede power for the first time in 47 years, saying his health is stable and the defense of the island guaranteed.

Chavez ended his conversation with his mentor telling him: "We will win time and win the battle for life."

"Fatherland or death. We will prevail!," the two leaders repeated after each other.