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.

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.

This week's talks in Cape Town were overshadowed by the absence of several key finance chiefs and foreign aid cuts by major economies like the United States and Britain. Disputes over trade, the Ukraine war and how to tackle climate change have long made it hard for the G20 grouping to make serious progress on global challenges.