Flavio Bolsonaro declared himself the "true elected president" of the country, claiming widespread electoral fraud and accusing Lula and the Supreme Court of "stealing" the election.
In a statement issued from the US, Bolsonaro said he left Brazil with his family because of fear of political persecution and vowed to lead the opposition from abroad.
He thanked Trump for granting asylum and called on the international community not to "normalize" what he described as an "authoritarian regime" in Brazil.