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.

Brazil plays 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.