Malaysia's Prime Minister Mahathir Mohamad shakes hands with Turkey's President Recep Tayyip Erdogan at Prime Minister Office in Putrajaya, Malaysia, December 18, 2019. Malaysia Department of Information/Handout via REUTERS

KUALA LUMPUR: Muslim nations need to do more business among themselves, trade in each other's currencies and keep up with non-Islamic countries to stop being left at their mercy, their leaders said on Thursday (Dec 19) at a summit boycotted by Saudi Arabia.