US President Donald Trump has announced a 50 percent tariff on Brazilian imports as he accused the country's leftist leadership of orchestrating a "witch hunt" against his right-wing ally, former leader Jair Bolsonaro.

Trump said the U.S. will impose an additional 10% tariff on any countries aligning themselves with the "Anti-American policies" of the BRICS group of developing nations, whose leaders kicked off a summit in Brazil.

Brazil is playing host to a summit of the BRICS bloc of developing economies Sunday and Monday during which pressing topics like Israel's attack on Iran, the humanitarian crisis in Gaza and trade tariffs imposed by U.