President Joe Biden will convene his national security team in the situation room on Monday afternoon as the US has warned its top Middle East ally Israel that an Iranian attack is imminent. The defense chiefs of both countries - Gallant and Austin - are also discussing a "series of scenarios and corresponding defensive, offensive capabilities." Biden also plans to speak with Jordan's King Adbullah, the White House has confirmed.

Axios has reported Sunday that the message being conveyed abroad by Secretary of State Antony Blinken is that while Washington doesn't know the exact timing of the the attacks, they could start as early as the next 24-48 hours, which would mean as soon as Monday.

Separately a Wall Street Journal was particularly alarming given it said that Iran has told Arab diplomats that "it didn't care if the response triggered a war" when they tried to urge deescalation and calm. Foreign ministers from Lebanon and Jordan have been in Iran trying to talk officials down from initiating a major attack.