The secretary-general of the Saudi-based Organization of Islamic Cooperation has resigned after making a joke about the purportedly frugal ways of Egypt's president.

The OIC said late Monday that Iyad bin Amin Madani resigned "for health reasons." However, his resignation comes as Egypt criticized Madani days earlier after he confused the Tunisian president's name with that of Egyptian President Abdel-Fattah el-Sissi, then said: "I am sure your fridge has more than water."

El-Sissi earlier had claimed that for a decade his fridge had nothing but water, in a message to Egyptians to bear harsh economic conditions.

The controversy comes as relations between Saudi Arabia and Egypt are strained over the wars in Syria and Yemen, as well as economic issues.

The 57-nation OIC is the largest body of Islamic nations.