"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.

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.

The BRICS bloc has criticized rising tariffs and attacks on Iran in its latest summit declaration. Meeting in Rio de Janeiro on Sunday, the group also condemned NATO’s increased military spending and expressed concerns about global trade disruptions caused by tariffs.