Chavez, 56, resisted opposition calls to temporarily hand the presidency of the South American OPEC member to his vice president during his absence. Instead, he delegated subordinates limited powers that included budgetary matters.

A former soldier whose long working hours and image of invincibility have helped him win numerous votes, Chavez is now visibly weakened as he plans a bid for re-election in 2012.

Chavez, who has said he had a large tumor removed in June in Cuba, boarded a flight to the Caribbean island on July 16 for chemotherapy. Chavez calls Cuba's Fidel Castro his mentor.

While he has not said what type of cancer he has or for how long he will be out of the country, he implied he would not stay for long.

"I should say that after the extraction of the tumor and all the studies that we have been doing rigorously until today ... no other malignant cell has been detected in my body," Chavez said at a rally where supporters and government ministers broke into tears.

"Based on the doctors' examination yesterday, in a few days we'll be back and ready for a final return," Chavez said.

His comments would indicate that the cancer has not become metastatic -- spread to other parts of the body -- and thus more dangerous and difficult to treat.

Chemotherapy refers to medical treatment using drugs intended to destroy cancer cells.

A source close to Chavez's medical team in Venezuela has said he is suffering from colon cancer that needs delicate treatment. But the government has not confirmed the type of cancer.