Chinese President Xi Jinping called on Brazil, Russia, India, China and South Africa (BRICS) to reject protectionism.
"We are facing a choice between cooperation and confrontation", he said.
That was the month Cyril Ramaphosa was elected head of the ruling African National Congress, enabling him to replace Jacob Zuma as president in February.
The BRICS countries comprise more than 40% of the global population but have never worked as a co-ordinated economic bloc.
Xi arrived in South Africa ahead of a summit of BRICS emerging economies - Brazil, Russia, India, China and South Africa - starting on Wednesday.
"A global trade war should be rejected because there will be no victor", said Xi, who oversees the world's second-largest economy, and whose nation is dominant in the BRICS bloc.
U.S. President Donald Trump has threatened to slap tariffs on all $505 billion worth of Chinese imports to his country, a move that has caused global concern.
Xi said China and South Africa were important emerging economies with similar perspectives on many global issues.
South Africa's trade and industry minister Rob Davies said other investments planned by China included an expansion of electronics firm Hisense's local operations and a metallurgical complex in Limpopo province.
The other leaders of BRICS countries - Russian President Vladimir Putin, Indian Prime Minister Narendra Modi and Brazilian President Michel Temer - are expected to join the three-day meeting in South Africa. "The same is what we are looking for from our BRICS partners". While they have combined foreign-exchange reserves of $4-trillion, the group's currencies, stocks and bonds took a hit from the trade war and the US Federal Reserve's policy tightening.
African leaders attending a "BRICS outreach" programme on Friday include Paul Kagame of Rwanda, Joao Lourenco of Angola, Macky Sall of Senegal and Yoweri Museveni of Uganda.
South Africa has invited the leaders of 22 additional countries to participate in this week's summit, including 19 from Africa. He cited the country's ranking at 21 on the World Bank's Doing Business 2018 report and Transparency International's Corruption Perception Index 2016, on which the UAE is ranked as the 24th least corrupt out of 176 assessed economies, as potential reasons.