The death toll from heavy rains that have caused flooding in Brazil's southern state of Rio Grande do Sul has risen to at least 78, local authorities said on Sunday, with more than 115,000 people displaced.

President Luiz Inacio Lula da Silva arrived in Rio Grande do Sul on Sunday morning with most members of his Cabinet to discuss rescue and reconstruction works with local authorities.

"Bureaucracy will not stand in our way, stopping us from recovering the state's greatness," Lula said at a news conference.