Brazilian President Luiz Inacio Lula da Silva joined South Africa in blasting Donald Trump for his threat to slap extra tariffs against the BRICS, escalating a spat with the US leader during the final day hosting the 10-member group.

The reimposition of Trump's higher tariffs, and also retaliatory measures from U.S. trading partners who did not reach a deal in time, threatens to pull global trade back to where it was in April, with widespread disruption, market volatility, and looming economic pain.