European Commission head Ursula von der Leyen also plans to mobilise a 4.7-billion-euro ($5 billion) investment package in South Africa that includes funding for a transition to clean energy and to boost vaccine manufacturing.

The EU-South Africa summit came at a time of "global uncertainty ... characterised by rising unilateralism, economic nationalism", South Africa's President Cyril Ramaphosa said in opening remarks that referenced a huge global shake-up since US leader Donald Trump took office.

There had been a retreat from "a world order that seeks to advance all nations" and promote a human rights culture, he said.

"If there ever was a time when it is absolutely necessary for partners who share the same values to work together, this is the time, particularly when multilateralism is under attack, particularly when the world order process is also being weakened," he said.

"This is the time to work together in defence of what we believe in, democracy, the rule of law, including the respect for international law and international humanitarian law."

"We should collectively strengthen our voice, working together," he said.

- 'Belief in human dignity' -

Both South Africa and the EU are grappling with dramatic policy shifts from Washington since Trump return to the White House this year, including on commitments to combat global warming, trade and tariffs, and Russia's war in Ukraine.

Trump's government has criticised South African policies and frozen crucial aid.

It has also imposed tariffs of 25 percent on steel and aluminium imports from EU and on Thursday threatened to impose a 200 percent tariff on wine, champagne and other alcoholic products from the 27-nation bloc.

The United States has meanwhile pulled out of a climate funding deal to help developing countries transition to clean energy, one of the main beneficiaries of which is South Africa.

Von der Leyen said the massive EU investment package included funding for a transition to clean energy including from the wind and sun and through the production of clean hydrogen.

It would also go towards ramping up vaccine manufacturing in South Africa, the continent's most industrialised economy and this year's president of the G20 grouping of leading economies.

"In a moment of increased global confrontation and competition, we must strengthen our partnership further," the EU chief said.

"We must work closely together, to ensure the future is built on our shared belief in cooperation and human dignity."

South Africa is the EU's largest trading partner in sub-Saharan Africa, exporting some 24 billion euros in goods in 2023, mostly minerals and automotive goods.

The trade deficit is nonetheless inclined in favour of the EU.