Prime Minister Benjamin Netanyahu said on Thursday that Israel was prepared for any "aggression" against it following threats of retaliation for the killings of top Hamas and Hezbollah figures.

"Israel is at a very high level of preparation for any scenario, both defensive and offensive. We will make any act of aggression against us pay a very high price... Those who attack us, we will attack in return," Netanyahu said in a statement.

Iran and armed groups backed by it are preparing coordinated action meant to deter Israel but avert all-out war, sources and analysts said, after the killings of top Hamas and Hezbollah figures.

On Wednesday, Iranian officials met in Tehran with representatives of the so-called "axis of resistance" -- a loose alliance of Tehran-backed groups hostile to Israel -- to discuss retaliation for the deaths of Hamas's leader and Hezbollah's top military commander, said a source close to Lebanese group.

The Iran-aligned "axis of resistance" against Israel and its allies have lost two major figures in less than 24 hours in attacks either blamed on or claimed by Israel.

Hamas political chief Ismail Haniyeh was killed on Wednesday in Tehran in a strike the group blamed on Israel, hours after top Hezbollah commander Fouad Shukur perished in an Israeli strike on southern Beirut.

Ismail Haniyeh was the international face of Hamas, its top leader in exile who kept up the militant group's ties with allies around the region. At the head of its political hierarchy, he had little military role – but Israel marked him for death after the surprise Oct. 7 attacks.

The 62-year-old Haniyeh was killed in an airstrike Wednesday during a visit to one of Hamas' most crucial allies, Iran, after attending the inauguration of its new president. Iran and Hamas both accused Israel, which has not commented on the strike.

A pair of assassinations of anti-Israel militant leaders hours apart is threatening to set off a regional clash and upend already fragile talks aimed at ending the war in Gaza.

The deadly round of strikes, retaliation and negotiations escalated Wednesday when Hamas' political chief, Ismail Haniyeh, was killed, hours after he attended the inauguration of Iran's new president in Tehran. Israel has not claimed responsibility, but Iran threatened revenge against Israel.

Two Al-Jazeera reporters were killed in an Israeli strike in northern Gaza on Wednesday, the satellite news network said, the latest Palestinian journalists working with the Qatari network to be killed in the war-torn enclave.

Correspondent Ismail al-Ghoul, 27, cameraman Rami al-Rifi and a child who was not identified were killed in a blast that struck a car in Gaza City that the three were traveling in, according to the network and the Emergency and Ambulance Service, which helps recover and transport casualties to hospitals across Gaza.

The Israeli military said Thursday that it has confirmed that the head of Hamas' military wing, Mohammed Deif, was killed in an airstrike in Gaza in July.

Israel targeted Deif in a July 13 strike that hit a compound on the outskirts of the southern Gaza city of Khan Younis, but the military said for weeks it was working to determine if he died in the blast. Hamas has denied he was killed. More than 90 other people, including displaced civilians in nearby tents, were killed in the strike, Gaza health officials said at the time.

Israel's suspected killing of Hamas' political leader in the heart of Tehran, coming after a week in which Prime Minister Benjamin Netanyahu promised U.S. lawmakers he would continue his war against Hamas until "total victory," points to an Israeli leader ever more openly at odds with Biden administration efforts to calm the region through diplomacy.

U.S. Secretary of State Antony Blinken, speaking on an Asia trip, was left to tell reporters there that Americans had not been aware of or involved in the attack on Hamas political leader Ismail Haniyeh, whose roles included overseeing Hamas' side in U.S.-led mediation to bring a cease-fire and release of hostages in the Gaza war.

By Asher Kaufman, University of Notre Dame

Israel's apparent assassinations of Fouad Shukur, Hezbollah's top military leader, in Beirut, and Hamas political leader Ismail Haniyeh, in Tehran, have raised again the specter of a regional war involving regional adversaries – one that could potentially drag the United States into the fray.

Israeli Prime Minister Benjamin Netanyahu is likely to benefit domestically from the killing of Hamas leader Ismail Haniyeh, but the escalation it could spark may reverse the win, experts said.

On Wednesday, the Islamist Palestinian movement and the Iranian Revolutionary Guards announced that Haniyeh, 61, had been killed in Tehran in an Israeli air strike.