US President Joe Biden said on Friday that the assassination of Ismail Haniyeh, head of the political bureau of Hamas, does not help reach a ceasefire agreement.

Biden, after phone calls with Israeli Prime Minister Benjamin Netanyahu and Turkish President Recep Tayyip Erdogan, expressed his deep concern about the tense situation in the Middle East.

During the call with Netanyahu, Biden stressed his country's commitment to Israel's security in the face of any threats from Iran.

The White House said in a statement that during the phone call, which was also attended by US Vice President Kamala Harris, Biden "stressed the importance of continued efforts to de-escalate tensions in the region."

The statement explained that "the president reaffirmed his commitment to Israel's security in the face of any threats from Iran, including from proxy terrorist groups such as Hamas, Hezbollah, and the Houthis."

During the conversation, Biden and Netanyahu also discussed “efforts to bolster Israel’s defense against threats, including those from ballistic missiles and drones.”

The statement indicated that supporting these efforts could involve "new deployments of American defensive weapons."

Joe Biden's National Security Adviser, Jake Sullivan, had previously indicated that the United States was "engaged in intensive efforts" to avoid an expansion of the conflict in the Middle East.

This phone call came amid calls for revenge against Israel, after it was accused of assassinating the head of the political bureau of the Hamas movement, Ismail Haniyeh, in Tehran at dawn on Wednesday, and its adoption of the liquidation of Fouad Shukr, one of the most prominent military leaders of Hezbollah, in an air strike that targeted the southern suburbs of Beirut.

Ismail Haniyeh was buried in Tehran on Thursday morning, and crowds of people participated in the funeral, which was headed by Iran's Supreme Leader Ali Khamenei, and called for revenge.

In the afternoon, Fuad Shukr, the commander of Hezbollah operations in southern Lebanon, was buried in the southern suburb of Beirut amid an angry crowd.

Hezbollah Secretary-General Hassan Nasrallah said Thursday that Israel should await the "inevitable response" to Shukr's assassination.

The killing of Haniyeh and Shukr raised fears of an escalation in the ongoing confrontation between Hamas and Israel since October 7.

Iranian officials discussed with representatives of pro-Tehran groups, including Hezbollah and Hamas, during a meeting held in Tehran on Wednesday, possible scenarios for responding to Israel, according to a source close to the Lebanese organization who is familiar with the content of the discussions.

According to the source, the attendees discussed “the possibility that the response would occur in parallel, meaning that Iran, Hezbollah, and the Houthis would bomb Israeli targets at the same time, or that each party would respond alone but in a coordinated manner.”

A leader in the "Islamic Resistance in Iraq" told Agence France-Presse that "Iran will lead the first response with the participation of factions from Iraq, Yemen and Syria against military targets, to be followed by a second response from Hezbollah."