(CNN) -- Venezuelan President Hugo Chavez is expected to begin radiation treatment Sunday in Cuba, where he underwent cancer surgery late last month.
Chavez flew to Havana late Saturday night. His treatment is expected to last about a month, he said in a message on state media before departing.
In February, Cuban doctors removed a tumor, which Chavez said was smaller than another tumor removed in June.
"I've decided, based on the recommendations of my medical and political teams, to begin ... radiation therapy as a complement to the surgery I had four weeks ago," the president said during comments broadcast by the Venezuelan state-run news channel VTV.
Chavez has not specified the type of cancer he is battling, and the government has released few specifics, fueling widespread speculation about his health and political future.
The 57-year-old outspoken, flamboyant socialist leader has led Venezuela since 1999 and has pledged to run for re-election in October.
His trip comes at the same time Pope Benedict is scheduled to visit the Caribbean island. The pope, who is on a six-day tour of Mexico and Cuba, is expected to visit Santiago de Cuba and Havana next week.
CNN's Patrick Oppmann contributed to this report.