is convalescing in seclusion at a Caracas military hospital, sent "guidance" to his cabinet as recently as Friday.
"He is staying informed and in charge as the chief who was ratified by our people various times," Maduro said at an event broadcast on state-run television.
The opposition says the government is lying about Chavez's condition and doubts Maduro's claim that Chavez held a five-hour meeting with his cabinet on February 22, giving orders in writing because a tracheal tube hinders his speech.
But Maduro repeated that the meeting took place. He insisted that the president sent more instructions the next day with science minister Jorge Arreaza, his son-in-law, before giving more guidance on Friday.
The leftist leader's chosen successor Maduro showed a dossier containing "political, social and economic actions" that Chavez has requested "to continue strengthening the economy to face the economic war of the parasitic bourgeoisie."
The "central document" will be sent to Chavez, he said, adding that the government was "respecting his treatment, we are not acting in an invasive way in his treatment."
Chavez, who was first diagnosed with cancer in the pelvic region June 2011, underwent a fourth round of surgery in Cuba in December. The government has never disclosed the exact nature, location and severity of the cancer.
Maduro revealed for the first time late Friday that Chavez began a new cycle of chemotherapy in January and decided to return to Caracas last month to continue a "more intense" phase of treatment.
Chavez was in "good spirits" but fighting for his life, Maduro said as he rejected growing rumors about the president's health.
One of Chavez's daughters, Maria Gabriela, responded Saturday to the publication online of a picture of her looking sad at the mass.
"Sadness? I can't be happy when my dad is sick! But I continue to cling to my God," she wrote on Twitter.
"At the next mass I will have to dance and laugh! I always thought that a mass was something something serious! People are very crazy," she wrote.
The once omnipresent leader has not come out in public in almost three months. Only four pictures were released, on February 15, showing him in his Havana hospital bed, smiling with his two daughters.
Around 50 university students have spent every night this week chained to each other in the middle of a Caracas streets, demanding that the government "tell the truth" about Chavez.
The government has accused the opposition and "fascist" foreign media of spreading rumors about Chavez to destabilize the nation sitting atop the world's largest proven oil reserves.
"We want to see Chavez recover and healthy, and we want him to be in peace, doing the treatment that needs to be done," said foreign minister Elias Jaua.
"Those who don't want Chavez to recover are those who use blackmail, criminal pressure, miserable pressure that we will not cede to," Jaua said.
Maduro, meanwhile, accused opposition leader Henrique Capriles of "conspiring" against Venezuela during trips to the United States and Colombia, and warned him not to "violate the rule of law."
He said Capriles, the Miranda state governor who lost to Chavez in the October presidential election, had met with "paramilitaries" in Colombia and was now in the United States.
The vice president said Capriles traveled to Miami and New York this weekend and was planning to meet Roberta Jacobson, the US State Department's top official for Latin America.