Donald Trump’s administration has revoked the visa of Brazil’s ambassador to the US in a sharp escalation of a diplomatic feud with the country’s president, Luiz Inácio Lula da Silva. The Trump administration stopped short of expelling Viotti, a former senior United Nations official. The Trump administration argues that Brazil has no right to interfere with the president’s choice of US ambassador to the country. “President Trump has the right to determine who represents the American people and interests around the world,” the state department said. Yet the state department insists that it still wants to restore a normal relationship with Brasília.