Joe Biden has been warned to prepare for a dual Iran–Hezbollah attack in retaliation for the death of Hamas’s political leader.

Ismail Haniyeh was killed by a short-range projectile at his home in Tehran hours after attending the inauguration of Iran’s new president.

The Islamic Republic has pledged to respond to the attack, with the US and Israel both on high alert as Tehran blamed Tel Aviv for Haniyeh’s death.

Senior American officials reported that President Biden had been advised Iran and its Lebanon-based proxy Hezbollah would likely unless two waves of attacks in the coming days.

It remains unclear who is likely to attack first and what type of strike either party intends to carry out.

In April following an Israeli attack on the Iranian Embassy compound in Syria, Iran launched 170 bomb-carrying drones, more than 30 cruise missiles and more than 120 ballistic missiles toward Israel.

Israel, the US and other nations shot down many of the projectiles, some of which came from Yemen.

Iran could launch a similar assault, but this time Hezbollah may get involved as the militia seeks revenge for the Israeli strike last week killing senior commander Fouad Shukur.

Such an assault could strain Israeli air defences, meaning more missile strikes raising the risk of casualties — and of a further escalation experts fear could lead to a wider regional war.

Mr Biden and Vice President Kamala Harris were briefed by their national security team on US military efforts to support Israel and US military forces in case of another attack by Iran and its proxies.

The briefing included a discussion of diplomatic efforts to reduce regional tensions and finalise a possible agreement for a ceasefire and hostage release.

President Biden and Ms Harris also received details about the attack on Al Asad Air Base in Iraq.

The base, which houses US troops in western Iraq, was targeted by a missile strike Monday evening, Iraqi and US security officials said.

The US military said in a statement that “initial indications” were that several US personnel were injured. The extent of their injuries was not immediately clear.

No group immediately claimed responsibility for the attack on the Ain al-Assad air base.