South African President Cyril Ramaphosa on Tuesday stressed the need for an effective, rules-based multilateral system to cope with the rise of extreme nationalism and neo-isolationism in some parts of the world.

The challenge before the world is to transform global politics from a power-based hierarchy to a rule-based international system where each country can advance and protect its national interest without provoking animosity, Ramaphosa said.

He was speaking at the annual South African Heads of Mission Conference taking place in Pretoria.

The very essence of the UN Charter is respect for international law and the principles of international justice, Ramaphosa said.

It is international law that informs the exercise and limits of the use of state power, and that enforces cooperation over conflict, and collaboration over confrontation, he said.

"If we are to safeguard our security and prosperity, if we are to silence the guns in Africa, we have to work to consolidate rather than erode the international rule of law," he said Ramaphosa.

It is only through collective effort, supported by multilateral institutions like the United Nations, that some of the world's most complex challenges have been addressed, the president said.

He said South Africa enthusiastically embraces its responsibilities as an active member of the UN.

This is particularly the case as South Africa prepares to enter the UN Security Council as a non-permanent member from 2019, he said.