(CNN) -- Former Brazilian President Luiz Inacio Lula da Silva, who remains a popular figure in his country, vowed in a video posted on YouTube to beat his recently diagnosed throat cancer.
The two-minute personal message was published Tuesday, the same day as Lula was released from the Syrian-Lebanese Hospital in Sao Paulo, where he underwent his first round of chemotherapy this week.
Doctors surgically inserted a port that allows the transfer of medicine straight to the former president's vein.
Lula then underwent his first chemotherapy session, which went "without incident," according to the hospital.
Doctors have said that they found a tumor located in Lula's larynx.
"I believe I will win this battle. This is not the first time and won't be the last battle I will face. With your solidarity, it's going to be much more peaceful, much easier," Lula said in the video, speaking in a raspy voice.
The thanked the Brazilian people for their outpouring of support.
"There is no space for pessimism or to feel sorry. If the day does not go well, with a lot of guts we will make it better tomorrow," he said.
Lula, known for the social programs he implemented at the same time that Brazil's economy soared, was Brazil's most popular president in recent history. His hand-picked successor, Dilma Rousseff -- a cancer survivor herself -- easily won the presidential election.