South Africa's G20 presidency this year will prioritise efforts to help developing countries finance their shift to a low-carbon economy, President Cyril Ramaphosa said, even as the United States radically scales back its support.

South Africa's President Cyril Ramaphosa called on Wednesday for strong cooperation at the opening meeting of the Group of 20 (G20) finance ministers in Cape Town, which was not attended by several key figures.

Finance ministers and central bank chiefs from the Group of 20 developed and developing nations have gathered in South Africa for a two-day meeting.