"Any Country aligning themselves with the Anti-American policies of BRICS, will be charged an ADDITIONAL 10% Tariff," Trump wrote on social media. BRICS members account for about half the world's population and 40 percent of global economic output.

Developing nations at the BRICS summit on Monday brushed away an accusation from President Donald Trump that they are "anti-American," with Brazil's president saying the world does not need an emperor.

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.