Canadian Prime Minister Stephen Harper also sent his condolences — although he pointedly offered hopes for a "a better, brighter future based on the principles of freedom, democracy, the rule of law, and respect for human rights."
Argentine President Cristina Fernandez declared three days of mourning nationwide. She and President Jose Mujica of neighboring Uruguay prepared to travel to Venezuela for the funeral.
In Nicaragua, a nation that broadly benefited from Venezuelan cut-rate oil, Rosario Murillo, the wife and spokeswoman of President Daniel Ortega, said Chavez is "one of the dead who never die."
"We are all Chavez," she said in televised comments.
Former U.S. President Jimmy Carter released a statement saying Chavez had a vision to bring "profound changes" to those in his country who were neglected and marginalized.
"Although we have not agreed with all of the methods followed by his government, we have never doubted Hugo Chavez's commitment to improving the lives of millions of his fellow countrymen," Carter wrote.
A wistful Rafael Correa, president of Ecuador and another of Chavez's closest allies, predicted Chavez would have a lasting influence. "We have lost a revolutionary, but millions of us remain inspired."
His influence extended beyond Latin America. Nabil Shaath, an adviser to the Palestinian president, called Chavez "a loyal friend who passionately defended our right to freedom and self-determination."
There was no shortage of emotional farewells to a socialist hero who some feel rivaled the revolutionaries of the 1960s.
Cuban folk singer Silvio Rodriguez quoted the title words of a famous musical ode to revolutionary Ernesto "Che" Guevara in bidding farewell to Chavez on his blog.
"Hasta siempre, comandante," he wrote, Spanish for "Farewell forever, commander."