The South African government has called on the International Crime Court (ICC) to issue an arrest warrant for Prime Minister Benjamin Netanyahu by mid-December.
Minister in the Presidency Khumbudzo Ntshavheni said if the ICC did not do this, it would signal a "total failure" of global governance.
"The world cannot simply stand by and watch," she said.
Israel says it is defending itself following the 7 October attack by Hamas which saw 1,200 people killed and more than 200 taken hostage.
It says it is trying to minimise civilian casualties but Ms Ntshavheni said the Israeli government was trying to "clear most of Gaza of Palestinians and occupy it".
South Africa, along with Bangladesh, Bolivia, Comoros and Djibouti, submitted a referral to the ICC to investigate whether war crimes and crimes against humanity have been committed in Gaza.
South Africa has long been a vocal supporter of the Palestinian cause.
The country has announced the withdrawal of its diplomats from Israel, and suggested that the position of Israel's ambassador to Pretoria was becoming "untenable".
