Venezuelan President Hugo Chávez arrived in Havana for medical treat-ment on Tuesday.
The Communist Party daily Granma reports that Chávez arrived during the night.
Chávez has spent much of the past 18 months fighting cancer.
In a written request to the legislature, Chávez said doctors recommended sessions of hyperbaric oxygen treatment to continue strengthening his health.
Chávez has said that tests earlier this year showed he was cancer-free. Medical experts say treatment in a hyperbaric chamber can help cancer patients recover from damage to nerves or muscles that can be caused by radiation therapy.