France, July 6 -- BRICS leaders meeting in Rio de Janeiro from Sunday are expected to decry US President Donald Trump's "indiscriminate" trade tariffs, saying they are illegal and risk hurting the global economy.

Emerging nations, which represent about half the world's population and 40 percent of global economic output, are set to unite over "serious concerns" about US import tariffs, according to a draft summit statement obtained by AFP.

Since coming to office in January, Trump has threatened allies and rivals alike with a slew of punitive duties. His latest salvo comes in the form of letters informing trading partners of new tariff rates that will soon enter into force.

The draft summit declaration does not mention the United States...