Egypt announced on Sunday it would back South Africa's genocide case against Israel at the International Court of Justice (ICJ), in a sign of Cairo's frustration over an Israeli military operation in Gaza's southern city of Rafah that borders Egypt.
The Egyptian Foreign Ministry said in a statement that the move comes "in view of aggravating intensity and scale" of Israeli attacks against civilians in Gaza and the "continued perpetration of systematic practices" against Palestinians, including direct targeting of civilians and destruction of infrastructure.
It was an "unprecedented humanitarian crisis," it added.
At the end of December, South Africa took Israel to the ICJ for alleged violations of the Genocide Convention during the Gaza War. In an interim ruling, the UN court ordered Israel to take protective measures to prevent genocide.
Israel has repeatedly rejected accusations of genocide and argues it invoked the right to self-defence after militants from Hamas and other extremist Palestinian organizations killed hundreds of civilians in Israel on October 7.
Egypt was the first Arab country to sign a peace treaty with Israel in 1979, but the military campaign in Gaza has inflamed anti-Israeli sentiment in the Arab world's most populous nation.
Earlier in the week, Israel took control of the Gaza side of the Rafah border crossing with Egypt, an operation that has halted humanitarian aid deliveries via the vital facility into the heavily populated strip.
Cairo is also concerned that a major Israeli incursion in Rafah, crowded by refugees fleeing the fighting in Gaza, would trigger a mass exodus into Egypt's Sinai Peninsula.
Israel deems Rafah the last stronghold of the Palestinian Islamist group Hamas.
Egypt's state-affiliated TV station al-Qahera News, citing a high-level source, reported that Cairo has refused to coordinate with Israel on aid entry into Gaza through the Rafah crossing because of the "unacceptable Israeli escalation."
Meanwhile, negotiations on a possible exchange of hostages held by Hamas for Palestinian prisoners in Israeli jails continued.
A high-ranking Israeli delegation arrived in Egypt on Sunday for this purpose, according to sources at the airport in Cairo. Like Qatar, Egypt has acted as a mediator in the war.