Israel and the United States are preparing for a potential Iranian attack on Israel as efforts to secure a ceasefire in Gaza intensify, with talks set to resume this week amid intense diplomacy to avert a wider regional war.

Mediators have urged Israel and Hamas to return to the negotiating table in a renewed push to strike a ceasefire deal after the talks risked being derailed by the recent assassinations of Hezbollah and Hamas leaders which Iran and its Lebanese proxy have vowed to avenge.

Negotiations are set to resume in the Egyptian capital Cairo or the Qatari capital Doha on Thursday. Last week, the United States, Egypt and Qatar – key mediators in talks between Israel and Hamas – said they will use the meeting to present a “final bridging proposal” and urged both sides to attend.

A major Iranian attack reprisal against Israel could risk derailing the ceasefire talks that US officials have said were at an advanced stage prior to the assassination of Hamas’ political leader Ismail Haniyeh in Tehran, which Iran blamed on Israel. Israel hasn’t confirmed or denied responsibility.

In a joint statement Sunday evening, France, Germany and the United Kingdom endorsed the calls for the warring parties to strike a deal, saying “there can be no further delay” given the simmering threat of a regional conflagration.

Whether the talks will proceed however is uncertain. Israel said it will send a delegation to the Thursday talks, but Hamas hasn’t confirmed attendance, even if has signaled that it still wants a deal.

Following Haniyeh’s assassination, Iran’s Supreme Leader Ayatollah Ali Khamenei said Haniyeh’s death would “not pass in vain,” and its Islamic Revolutionary Guard Corps warned that “blood vengeance” for the killing is “certain.”

There have been some indications that Iran may abandon plans to attack Israel if a ceasefire deal is reached. But the country’s mission to the United Nations said on Saturday that Tehran’s retaliation to Israel’s suspected killing of Haniyeh is “totally unrelated to the Gaza ceasefire,” adding that it has a right to self-defense.

The US and Israel continued preparations for that scenario over the weekend. US Defense Secretary Lloyd Austin ordered a guided missile submarine, the USS Georgia, to the Middle East and accelerated the arrival of a carrier strike group to the region, the Pentagon said Sunday evening. The US also released $3.5 billion to Israel to spend on US weapons and military equipment, months after it was appropriated by Congress. And on Monday, the Israeli military suspended vacation flights for permanent personnel in anticipation of an attack.

Iran’s UN mission said it hopes that its attack on Israel “will be timed and conducted in a manner not to the detriment of the potential ceasefire.”

“Direct and intermediary official channels to exchange messages have always existed between Iran and the United States, the details of which both parties prefer to remain untold,” it added.

Meanwhile, Hezbollah – the Iran-backed militant group in southern Lebanon – fired a barrage of about 30 rockets toward northern Israel Sunday night. Although rocket fire toward Israel from Lebanon has become a near-daily occurrence since the outbreak of war in Gaza, Israeli officials fear a larger-scale response from Hezbollah after the assassination of the group’s top military commander Fu’ad Shukr in a Beirut suburb last month

But as the world watched Iranian airspace and the Israel-Lebanon border, the worst of the weekend’s fighting was again confined to the Gaza Strip, as an Israeli strike on a mosque and school in Gaza City killed at least 93 Palestinians on Saturday, according to local officials.

With the number of Palestinians killed during 10 months of war edging closer to 40,000, Israel’s strike sparked global condemnation. Qatar and Egypt condemned the strike, calling it a violation of international law, and the US National Security Council said the White House was “deeply concerned” about reports of civilian casualties.” In the aftermath, the three mediators renewed their calls for the warring parties to agree to a ceasefire deal.

Although the Israel Defense Forces (IDF) said it had targeted a Hamas command post and killed several fighters, the strike was a reminder that, despite its earlier claims to have dismantled Hamas in the north of the Strip, the militant group has reassembled in areas previously deemed clear.

Renewed talks

After Haniyeh’s assassination, Hamas named Yahya Sinwar – its leader in Gaza and one of the masterminds of the October 7 attack on Israel – as the new head of its political bureau, suggesting that Hamas’ most extreme faction had taken over, further dimming hopes of a ceasefire deal.

But, following the call from mediators last week to return to talks, Hamas requested a plan to implement the existing offer proposed by US President Joe Biden in July, rather than pursuing additional negotiations.

“Out of concern and responsibility towards our people and their interests, the movement demands the mediators to present a plan to implement what they presented to the movement and agreed upon on July 2, 2024, based on Biden’s vision and the UN Security Council resolution, and to compel the occupation (Israel) to do so, instead of going for further negotiation rounds or new proposals,” Hamas said in a statement Sunday.

But, despite growing pressure at home to help bring the hostages home, Israeli Prime Minister Benjamin Netanyahu has repeatedly stymied attempts to reach an agreement.

“Nobody knows what Bibi wants,” one Israeli source said, calling Netanyahu by his nickname.