(CNN) -- Hugo Chavez has returned to Venezuela after his latest trip to Cuba for cancer treatment.
The Venezuelan president made the announcement after arriving at the Simon Bolivar International Airport near Caracas on Friday night.
"We successfully completed the entire cycle of radiotherapy, as it was planned by the medical team," Chavez said. "Other than some discomfort -- normal during this treatment -- nothing forced myself to stop, suspend or alter the initial plan, as it is fully completed."
Neither Chavez, 57, nor anyone in his government have publicly discussed what kind of cancer he has.
Contrary to some rumors that Chavez was unable to walk, the president walked down from airplane stairs Friday night wearing a blue-and-white jacket, black-and-white pants and tennis shoes.
Chavez said he needs to continue following doctors' orders "so I can recover from the normal effects, the expected effects, from the radiotherapy treatment."
The president said he was optimistic about his treatment and said he hoped to "continue serving God's command ... to continue building with you a new country, the socialist homeland, the Venezuelan homeland."
The president also mentioned opposition members and said he is following them very closely.
"The right seems exhausted, desperate, like exhausted fighters -- throwing punches, but desperate," Chavez said. "We must be careful with their manifestations."
He added, "an opposition without leadership, without feet or head, without logic ... they are so desperate that they are trying to generate violent acts, even some of their leaderships announce it. They are traveling in some parts of the world trying to articulate a kind of axis against Venezuela, do not lose sight."
In a lighter tone, the president ended his speech by singing a song for Mother's Day.
Chavez has spent more than 50 days undergoing treatment in Havana this year alone, according to a CNN tally. Last year, he spent 45 days there.
Chavez left for Cuba on April 30 and spent 11 days in treatment.
CNN's Catherine E. Shoichet contributed to this report.