President Donald 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 major summit in Brazil on Sunday.

BRICS now accounts for 45 per cent of the global population and contributes over 35 per cent to the world’s GDP.

Brazil's President Luiz Inácio Lula da Silva has some of his priorities, such as debates on artificial intelligence and climate change, front and centre for certain talks.