A summit of leaders from the BRICS group of major emerging economies kicks off in Brazil Sunday – but without the top leader of its most powerful member.

For the first time since taking power, Chinese President Xi Jinping is skipping the BRICS Summit, sending Premier Li Qiang to Rio de Janeiro in his place. Xi’s absence raises questions amid global trade turmoil and U.

As Russian President Vladimir Putin and Chinese leader Xi Jinping skip the BRICS Summit in Brazil, here’s how the expansion of the group has led to the emergence of an ideological divide.