Brazilian President Luiz Inacio Lula da Silva on Thursday slammed Donald Trump's threat to impose 50 percent tariffs on Latin America's largest economy as "unacceptable blackmail."In his speech, leftist leader Lula slammed Brazilian politicians who back Trump's policies as "traitors to the homeland.

The U.S. Trade Representative (USTR) has launched Section 301 investigation against what it said are potentially unfair trade practices used by Brazil, just days after U.S. President Donald Trump threatened 50 percent tariffs on the country over claims it was treating former President Jair Bolsonaro unfairly.

Trump announced a sweeping 50 percent tariff on all Brazilian exports to the United States beginning Aug. 1. In a letter to Luiz Inácio Lula da Silva, the left-wing leader who defeated Jair Bolsonaro three years ago,