Lula said voters should think about what kind of South America they want to create before heading to the polls to decide the presidential race between Economy Minister Sergio Massa and far-right economist Javier Milei.

Milei has questioned Argentina's relationship with Brazil, calling Lula a "communist", and has publicly criticized the South American common market Mercosur, saying that Argentina would "follow its own path."

"Argentina is very important to Brazil," said Lula in a weekly livestream on social media.

"Argentina and Brazil need each other. We need to be together, without differences. When we have disagreements, we sit down at a table, negotiate and end the disagreement. That's how I've lived with Argentina until now," he said.

Lula called on Argentine voters to think carefully about their decision.

"We need a president who likes democracy, who respects institutions, who likes Mercosur, who likes South America and who thinks about creating an important bloc. Today the world is divided into blocs, the European bloc, the Asian bloc. We need to create our own bloc to trade with the rest of the world," he said.

Milei, dubbed "Argentina's Bolsonaro" because of his ideological affinity with Brazil's former far-right President Jair Bolsonaro, has said in campaign speeches that he would limit trade with Brazil if elected.

He has called Lula an "angry communist" and a "socialist with a totalitarian vocation".

By contrast, Massa has warmer relations with the Lula government and has met in Brasilia with Brazilian Finance Minister Fernando Haddad to discuss Buenos Aires' relationship with the International Monetary Fund (IMF).