Venezuelan President Hugo Chavez is back in Cuba for more cancer treatment, officials say. Chavez arrived in Havana late Saturday evening and was welcomed by Cuban President Raul Castro, Voice of America reported. The Venezuelan president had a large tumor removed by doctors in Cuba in June, followed by a first round of chemotherapy in July. His second round of chemotherapy was to have taken place Sunday, CNN reported. Venezuelan National Assembly held a special meeting to give Chavez the go ahead for his trip, which could last several days. Lawmaker authorized the trip unanimously within 10 minutes, the Latin American Herald Tribune reported. "We ratify for reasons of legality, legitimacy and humanity the approval of all parts of the president's request," said Fernando Soto Rojas, president of the National Assembly. Legally, the president of Venezuela is not allowed to leave the country for more than five days without the permission of the legislature. Chavez put in his request Friday.