French President Emmanuel Macron proposed on Tuesday that an international coalition fighting against Islamic State in Iraq and Syria be widened to include the fight against the Palestinian group Hamas in Gaza.
Macron gave no detail on how the US-led coalition of dozens of countries, of which Israel is not a member, could be involved.
Speaking alongside Israeli Prime Minister Benjamin Netanyahu in Jerusalem, Macron stressed that France and Israel shared terrorism as their "common enemy".
"France is ready for the international coalition against Daesh in which we are taking part for operations in Iraq and Syria to also fight against Hamas," he told reporters, referring to Islamic State.
Macron, who warned against the risks of a regional conflict, also said the fight against Hamas "must be without mercy but not without rules".
Israeli Prime Minister Benjamin Netanyahu did not directly comment on Macron's proposal but said the fight was a battle between the "axis of evil" and "the free world".
"This battle is not merely our own ... it's everybody's battle," he said.
The US-led coalition fighting Islamic State was formed in September 2014.
What began as a major military operation that helped "deliver the military defeat of Daesh in Iraq and Syria", is now focusing on advising and assisting local partners, including with reconnaissance and intelligence, to ensure the group cannot reclaim lost ground, the coalition says on its website. It operates primarily in Iraq.
Thirty French citizens were killed by Hamas men in their attack on southern Israel on 7 October, in which more than 200 people were seized and 1,400 people killed. The Palestinian health ministry says Israeli air strikes on Gaza have killed over 5,000 people since then.
The French president, who met families of French victims at Tel Aviv airport, said freeing nine French hostages was a priority for France.
Macron wanted to make proposals to prevent an escalation of the war, to free hostages, and guarantee Israel's security and work towards a two-state solution, presidential advisers said. He will push for a humanitarian truce, they added.
Macron's visit to Israel comes after EU foreign ministers on Monday struggled to agree on a call for a "humanitarian pause" in the war.
He will meet with other regional leaders in Jordan's capital Amman on Tuesday. Mahmoud Abbas' office said Macron would also meet the Palestinian leader in Ramallah, in the West Bank.
However, the French government's decision to adopt a blanket ban on pro-Palestinian protests, before it was struck down by the courts, is one reason Macron has lost credit in the Arab world, Karim Emile Bitar, a Beirut-based foreign policy expert at French think tank IRIS said.
French officials contest the idea that Macron's policy is biased. They say Macron has constantly reaffirmed the rights of Palestinians and the position of a two-state solution.