A military response from the US could threaten the ceasefire that has been in place since 8 April, as Tehran warned "foreign forces" to leave the Strait of Hormuz.

In a statement posted to social media, U.S. Central Command said the strikes would be “a proportional response to unjustified Iranian aggression.”

The alleged shoot-down came hours after a US fighter jet fired on a Palau-flagged commercial tanker accused of attempting to outrun the US blockade of Iran.

Trump has repeatedly said Iran wants to make a deal with him to end the war and that they have agreed to concessions.