Venezuelan president Hugo Chavez rallied tens of thousands of supporters, wearing his signature red beret and singing a folk song as he launched his re-election bid.
Mr Chavez waved and blew kisses to crowds while he rode atop a truck to the country's elections office, then picked up a document registering as a candidate.
Afterward, he stepped onto a stage and energetically sang along with a band to a traditional tune from the rural plains where he was born. Mr Chavez laughed and danced briefly on stage.
The 57-year-old president, a former army paratroop commander first elected in 1998, is seeking another six-year term in the October 7 presidential vote.
His struggle with cancer has recently forced him to scale back his public appearances and has raised questions about whether his health may interfere with the re-election campaign.
“I want to thank my Lord that I'm here today. ... It was a difficult year,” Mr Chavez said in a speech to cheering crowd. “Here I am, before you again!”
He denied rumours of worsening health, calling such speculation “psychological warfare” waged by his adversaries.
“We're just warming up our engines,” he said, vowing to win the vote in a “knockout”.
As Mr Chavez registered his candidacy, he walked slowly greeting allies and elections officials. The crowd outside chanted: “Ooh-Ah! Chavez's isn't going away!”
His supporters and government employees wore their socialist party's red caps and shirts, holding photos of the president and signs reading: “We're giving it our all, out of love for Chavez.”
Three giant inflatable likenesses of Mr Chavez rose above the crowd that surrounded the elections office.
Mr Chavez wore a track suit in the yellow, blue and red of Venezuela's flag as he rode through streets lined with supporters on his way to the elections office.
Confetti floated in the air as he passed. Some in the crowd waved flags, and others blew whistles and horns.
Mr Chavez was accompanied by relatives including his brother Adan and two daughters.