South Africa is determined to pursue its genocide case against Israel at the International Court of Justice and will next month file more evidence, President Cyril Ramaphosa said Friday.

South Africa filed the case in December alleging that Israel's Gaza offensive, launched in retaliation for Hamas' bloody October 7 attack, breached the 1948 UN Genocide Convention.

Israel has strongly denied the accusation.

"We are headstrong," Ramaphosa told journalists when asked about the case. "We are determined to go ahead with our case."

The country is due to file facts and evidence to the UN court next month to back up its case.

"Preparations are underway to present what they call the memorial, a huge tome of hundreds and hundreds of pages," the president said.

"We continue arguing that the genocide must stop and there must be a ceasefire, and similarly, there must be a return of the hostages."

South Africa's case has been joined by several countries, including Colombia, Libya, Mexico, Spain and Turkey.

Hamas's attack on Israel resulted in the deaths of 1,205 people, mostly civilians, according to an AFP tally based on official Israeli figures. The count includes hostages killed in captivity.

Israel's retaliation has killed at least 41,118 people in Gaza, according to the territory's health ministry.