“If something does happen this week, the timing of it could certainly well have an impact on these talks we want to do on Thursday,” he added.

At the weekend, Hamas cast doubt on whether talks would go ahead. Israel and Hamas have held several rounds of talks in recent months without agreeing a final ceasefire.

In a sign of further resistance to an end to fighting between Israel and Hamas, on Wednesday AEST official from the group said it will not take part in the round of cease-fire talks, and accused Israeli Prime Minister Benjamin Netanyahu of negotiating in bad faith.

“Netanyahu is not interested in reaching an agreement that ends the aggression completely,” Abdul Hadi said, according to the New York Times. “But rather he is deceiving and evading and wants to prolong the war, and even expand it at the regional level.”

In Israel, many observers believe a response is imminent after Supreme Leader Ayatollah Ali Khamenei said Iran would “harshly punish” Israel for the strike in Tehran.

“We are closely following what happens in Beirut and Tehran, and are working to thwart any (possible) threat, while also preparing a variety of offensive options,” Israeli Defence Minister Yoav Gallant said during a visit to an intelligence base in Northern Israel.

Two of the Iranian sources said Iran would support Hezbollah and other allies if they launched their own responses to the killing of Haniyeh and Hezbollah’s top military commander, Fuad Shukr, who died in a strike in Beirut the day before Haniyeh was killed in Tehran

Reuters with Chris Zappone