Either is deeply embarrassing for the regime which says Israel crossed a red line with its alleged attack.

Three US and Israeli officials told the Axios news outlet they expect Iran to attack Israel as early as Monday.

According to Axios, the US is also leading plans to draw on support from friendly countries in the region similar to how it did in April when Jordan, Saudi Arabia and Britain [among others] helped blunt the attack involving hundreds of projectiles from Iran.

Iranian media have been widely reporting that this attack aims to be more devastating than April’s, with Tel Aviv and other cities not off limits.

On Saturday, Joe Biden, the US president, was asked by reporters whether he thinks Iran will stand down. “I hope so. I don’t know,” he said.

The French foreign ministry statement said: ”In a highly volatile security context … we invite [French citizens] to make arrangements now to leave Lebanon as soon as possible,” adding that some commercial flights from Beirut to France were still available.

To its nationals living in Iran, France urged them to “temporarily leave” due to the risk of “Iranian airspace and airports being closed”. The new warnings came two days after all French visiting the Islamic Republic were told to leave.

On Saturday, David Lammy, the British foreign secretary, issued a warning to “leave now” with fears that “the situation could deteriorate rapidly”.

Air France and Transavia France, along with Lufthansa, are among the airlines that have suspended flights to and from Beirut.