JOHANNESBURG, Aug 17 (Reuters) - BRICS leaders meet in South Africa next week to discuss how to turn a loose club of nations accounting for a quarter of the global economy into a geopolitical force that can challenge the West's dominance in world affairs.

Russian President Vladimir Putin, who faces an international arrest warrant over alleged war crimes in Ukraine, will not join leaders from Brazil, India, China and South Africa amid rifts over whether to expand the bloc to include dozens of "Global South" nations queuing up to join.

South Africa will host Chinese President Xi Jinping, Brazil's Luiz Inacio Lula da Silva and Indian Prime Minister Narendra Modi for the BRICS summit from August 22 to 24.

Spread over the globe and with economies that operate in vastly different ways, the main thing uniting the BRICS is scepticism about a world order they see as serving the interests of the United States and its rich-country allies who promote international norms they enforce but don't always respect.

Few details have emerged about what they plan to discuss, but expansion is expected to be high on the agenda, as some 40 nations have shown interest in joining, either formally or informally, according to South Africa. They include Saudi Arabia, Argentina and Egypt.