( CNN ) -- Venezuelan President Hugo Chavez arrived in Havana early Wednesday for a new round of medical treatment , Cuban state media reported . The timing of his departure , weeks before regional elections in Venezuela , has fueled renewed speculation about the president 's health . It was unclear how long Chavez , who declared himself cancer-free in July , would remain in Cuba . `` Nobody should be alarmed . Nobody should worry . This is part of the treatment that the comandante has been following , '' said Diosdado Cabello , president of Venezuela 's National Assembly and a close Chavez ally . Chavez will undergo several sessions of hyperbaric oxygen therapy , state media said . The treatment helps prevent and mend bone damage caused by radiation therapy , according to the American Cancer Society . It involves breathing pure oxygen in a sealed chamber that has been pressurized at up to three times normal atmospheric pressure . Chavez underwent several rounds of radiation therapy in Havana earlier this year . The Venezuelan president repeatedly spoke publicly about his cancer battle , but he never specified what type of cancer doctors were treating . Members of Venezuela 's opposition wished Chavez good health but criticized him Wednesday for a lack of transparency regarding his health and treatment . `` I think that he should speak to the Venezuelan people with transparency about what the situation is , what the scope of this treatment is , '' said Henrique Capriles Radonski , who faced off against Chavez in October 's presidential election and is now vying for governor in Venezuela 's Miranda state . `` This is how it should be in Venezuela , and you can see that it 's like this in other countries . '' Cabello defended Chavez and said such criticism was unwarranted . `` The president has been very clear with the Venezuelan people about the illness he has and how it has been treated , '' he said . Health rumors dogged Chavez on the campaign trail this year , but did n't stop him from winning re-election in October . From June 2011 to May 2012 , he underwent cancer treatment in Cuba , raising speculation about his political future and about a possible successor , especially when he named 10 people to his inner circle of advisers , known as the Council of State . But Chavez declared himself cancer-free in July and went ahead with his campaign . Details of his health , however , have been a closely held secret , and some people who claim to have insider knowledge say the president is in much worse condition than he publicly lets on . The National Assembly on Tuesday voted to grant Chavez permission to travel to Cuba for the treatment , the state-run AVN news agency reported . Word of Chavez 's trip to Cuba sparked debate on the streets of Caracas , the capital . Chavez used to appear much more frequently on national television , said Hedbert Cortes , a worker . `` Before he would talk on TV for hours . Now he 's on less . I think this is because of his health , '' Cortes said . Andres Berroteran said he was hoping for the best for Chavez . `` That everything turns out well and he recuperates , '' the insurance analyst said . `` Like any human being , we wish him the best . '' Chavez slams Venezuelan opposition after election victory . Journalist Osmary Hernandez and CNN 's Patrick Oppmann , Claudia Dominguez and Nelson Quinones contributed to this report .
State news : Hugo Chavez will receive several sessions of hyperbaric oxygen therapy . Chavez is in Cuba for ` ` medical treatments , '' state media reports . The government says he is cancer - free , but some doubt that . His condition has been a closely guarded secret .