JOHANNESBURG—With Africa’s most poverty-stricken economies pushing for financial debt relief as they battle with the fallout from the world coronavirus pandemic, a tussle is brewing among made nations, personal traders and the continent’s premier creditor: China.

Rich international locations from the U.S. to Japan—watching their own economies lurch towards recession—are loath to forgive African financial debt if they imagine the money will indirectly help Chinese lenders, like the govt, banking institutions and contractors. At the same time, Beijing…