"They're complex treatments... that should at some point begin to close the cycle of treatment for his illness," vice president Nicolas Maduro said on television, without giving details.
Maduro spoke after returning on Wednesday from a trip to Cuba, where Chavez continues to receive medical care. Maduro said he had met with the president's doctors and relatives. He said that the president's elder brother, Adan, had also returned from Cuba to Venezuela on Wednesday.
Chavez hasn't been seen or spoken publicly since December 10, when he traveled to Havana for the operation.
Venezuelans on both sides of the country's political divide have been speculating about the socialist leader's condition amid vague reports about his health.
Information minister Ernesto Villegas had said on January 26 that during the surgery a "malignant lesion" was removed from Chavez's pelvis and that his recovery has been favorable. Villegas also said that Chavez had begun "systemic medical treatment for the fundamental illness."
Medical experts consulted by The Associated Press have said the government's account of "systemic medical treatment" could mean various types of chemotherapy or drug treatments, depending on the type of cancer.
Chavez has had tumors repeatedly removed from his pelvic region, and has also undergone prior rounds of chemotherapy and radiation treatment. The 58-year-old President hasn't revealed the type of the cancer or the precise location of the tumors removed.