Israel has been braced for an Iranian assault on five fronts 'at any moment' in revenge following the assassination Wednesday of Ismail Haniyeh, the leader of the Palestinian Islamist group Hamas, in Tehran a day after an Israeli strike in Beirut killed Fuad Shukr, a senior military commander from the Lebanese group Hezbollah.

The White House Press Office and Joe Biden's own social media accounts said that the president and Kamala Harris have been briefed by national security advisors on the attack. 

'They discussed the steps we are taking to defend our forces and respond to any attack against our personnel in a manner and place of our choosing,' a spokesperson said.