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.

The BRICS leaders voiced "serious concerns about the rise of unilateral tariff and non-tariff measures," warning they are illegal and arbitrary, according to a final summit statement.

Voicing "serious concerns about the rise of unilateral tariff" measures, BRICS members said the tariffs risked hurting the global economy, according to a summit joint statement.