Brazilian politician Luiz Inacio Lula da Silva has been sworn-in for a third term as Brazil's president in the capital Brasilia.

Lula arrived at the Sunday's ceremony in a presidential Rolls Royce, closely flanked by security officers, alongside the Vice President-elect Geraldo Alckmin.

"I promise to maintain, defend and fulfill the Constitution, observe the laws, promote the general good of the Brazilian people, uphold the unity, integrity and independence of Brazil," said Lula in a lengthy speech.

Lula thanked the Brazilian people for the confidence that they had shown by voting him in for a third term.