Israel has declined earlier to comment on Haniyeh’s killing in Iran, though it has acknowledged its responsibility for assassinating the senior Hezbollah leader Fouad Shukr in an air strike on southern Lebanon.

"White House officials responded with surprise and outrage to Haniyeh’s assassination, which they saw as a setback to their months-long quest to secure a ceasefire in Gaza, which is a fitful process they believed was making progress," three people familiar with the White House’s thinking told Washington Post.

An Israeli official confirmed that a call between US President Joe Biden and Israeli Prime Minister Benjamin Netanyahu last week, after Haniyeh’s death, was “tense.”

Israeli Channel 12 news reported that Biden told Netanyahu to stop bullshitting him, during their phone conversation.

The Israeli outlet said that the outburst had come after Netanyahu told Biden that Israel was moving forward with negotiations on a ceasefire deal with Hamas and would soon send a delegation to resume talks.

The New York Times reported that Biden had said during the call that the assassination of Haniyeh in Iran was “poorly timed,” coming “right at what the Americans hoped would be the endgame” of talks for a ceasefire and captives release deal.

The Israeli assassination occurred shortly after Netanyahu's returning from a trip to Washington, where he addressed the US Congress and met with Biden, adding up new demands in the negotiations concerning Gaza that make an accord harder to reach. 

Biden had previously accused Netanyahu of dragging out the war in Gaza to remain in power.

Moreover, senior Israeli officials, including Defense Minister Yoav Gallant and Army Chief Herzi Halevi, told Netanyahu that his insistence on "new terms" would sabotage the ceasefire-captive deal currently under negotiation.

Throughout the war, Israel has repeatedly launched strikes on Hezbollah and Iranian commanders in Syria without first informing the United States, enraging Biden officials and the president himself, the Post said.

Still, there are no signs that Biden is willing to exert significant pressure on Israel to try to contain its actions, such as conditioning or limiting military aid, according to several people familiar with internal discussions.

On Tuesday, Hamas announced that Yahya Sinwar — already the leader of Hamas in Gaza and the architect of the Al-Aqsa Flood Operation on 7 October  — would replace Haniyeh as head of the group’s political bureau.

Analysts have noted that, unlike Sinwar who lives in Gaza, Haniyeh lived in Qatar and travelled abroad, deepening questions about why Netanyahu would have chosen this critical moment to strike.

“If your aim was to close the deal, why do Haniyeh now and do it in a way that forces the Iranians to respond?” Dennis Ross, a former American envoy to Israel told Washington Post.