Santos, flanked by his wife Maria Clemencia Rodriguez and their daughter Maria Antonia, told reporters as he arrived at the Santa Fe Hospital that he was upbeat and "God willing, everything will go well."

After the operation, Santos's doctors said: "It was a successful surgery, without complications. The president is conscious in his room with his family and is recovering."

Santos, 61, announced on Monday that he had prostate cancer, noting that the tumor was small and had been caught in time, giving him a 97 percent chance of full recovery.

Urologist Felipe Gomez, who was in charge of the surgery, said before the operation that it would likely take about four hours.

Santos said that since he was to receive a local anesthetic, he would not delegate his powers as head of state.

He has said doctors have advised him not travel for a few weeks after the operation but that otherwise his overall health is not in jeopardy.

Santos is just the latest in a long line of Latin leaders to undergo cancer treatment in recent years.

In Brazil, Dilma Rousseff and her predecessor Luiz Inacio Lula da Silva both have undergone treatment. So did Paraguay's now ex president Fernando Lugo, and Venezuela's Hugo Chavez, who is now battling for re-election October 7.

Argentina's Cristina Kirchner in late 2011 announced she had thyroid cancer and underwent surgery before later disclosing that she had been misdiagnosed.