President Ramaphosa joined most of the world's leaders in defending the United Nations on Tuesday as the 73-year-old global institution came under the strongest attack yet from an American President.

Addressing the UN General Assembly for the first time as South African president, Cyril Ramaphosa once again invoked the spirit of Nelson Mandela, recalling what the first president of a democratic South Africa had said about the UN in this same hall 24 years ago.

"The millions across our globe who stand expectant at the gates of hope look to this organisation, to bring them peace, to bring them life, to bring them a life worth living," Mandela had said.

Marking the centenary of Mandela's birth, the world had to ask if the United Nations "has met the needs and the expectations of the millions who stand at the gates of hope", Ramaphosa said.

It should also ask if the UN had contributed to a more peaceful, prosperous and equal world. And the world was called upon...