French President Emmanuel Macron on Wednesday gave a lukewarm reception to an Israeli request to criticize the International Criminal Court, saying he would study the matter.

Macron’s response dealt a setback to Israeli Prime Minister Benjamin Netanyahu’s hopes for a strong backlash against the ICC by world leaders gathering in Jerusalem for a memorial service marking the 75th anniversary of the liberation of the Auschwitz death camp.

The court’s chief prosecutor, Fatou Bensouda, said last month that there was a “reasonable basis” to open a war crimes probe into Israeli military actions in Gaza as well as settlement construction in the West Bank. She has asked the court to determine whether she has territorial jurisdiction before proceeding with the case.

On Tuesday, Netanyahu said he was urging the world to take “concrete actions” against the ICC.

He called the investigation a “full frontal attack” on Israel’s right to defend itself and what he said is the right of Jews to live in their “ancestral homeland.” The international community considers the West Bank, captured by Israel in 1967, to be occupied territory.

Speaking to reporters outside a Jerusalem church, Macron said the Israeli side had made a “very strong request” during meetings with Prime Minister Benjamin Netanyahu and President Reuven Rivlin earlier in the day.

Macron said he understands the Israeli arguments but needed time to formulate a response.

“I will give them my response when I have better knowledge on the file,” he said.