Venezuelan President Hugo Chavez left for Cuba late Saturday to begin chemotherapy, after undergoing surgery last month to remove a cancerous tumor.

Before boarding his plane, Mr. Chavez said he was going away for a few days, but the length of his stay in Cuba is not known.

Earlier in the day, President Chavez delegated some of his powers to Vice President Elias Jaua and Finance Minister Jorge Giordani, after the national assembly approved his trip. He resisted calls from the opposition to temporarily hand over the presidency to the vice president during his absence.

Mr. Chavez returned from Cuba where he had surgery to remove the tumor on July 4, one day before Venezuela celebrated the 200th anniversary of its independence from Spain.

The Venezuelan leader did not indicate the type of cancer he had, and questions remain about how sick he is. Prior to that surgery, Mr. Chavez underwent an operation in Cuba for what officials said was an abscess in his pelvic area.

The 56-year-old president, who has ruled the South American nation since 1999, told Venezuelans that he intends to remain in control of the country.