Venezuela's foreign minister demanded Saturday that President Hugo Chavez be allowed to recover in peace after the government revealed for the first time that the cancer-stricken leader was in chemotherapy.

Foreign Minister Elias Jaua said Chavez, 58, was in a "battle" to recover as the socialist leader rests in a Caracas military hospital, where he checked in on February 18 after two months of treatment in Cuba.

"We want to see Chavez recover and healthy, and we want him to be in peace, doing the treatment that needs to be done," Jaua said on state-run television as he visited a school in Caracas.

"Those who don't want Chavez to recover are those who use blackmail, criminal pressure, miserable pressure that we will not cede to," he said, referring to the opposition, which accuses the government of lying about the president's health.

Vice President Nicolas Maduro disclosed 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 after a mass in a new chapel of "hope" within the military hospital grounds, as he rejected growing rumors about the president's health.

One of Chavez's daughters, Maria Gabriela, responded Saturday to 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.

Chavez underwent on December 11 the fourth round of surgery since he was first diagnosed with cancer in the pelvic region June 2011. The government has never disclosed the exact nature, location and severity of the cancer.

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.

[Image via Agence France-Presse]