Washington | President Donald Trump said Wednesday that oil prices that have surged because of the Iran war likely won't come down until after US midterm elections.

Oil prices jumped more than 3% today, pushing international Brent crude past the $100 threshold for the first time since July as salvos between the US and Iran escalated.

Trump, in an exchange with reporters before traveling to Dallas for the midterm Republican convention, added that he believes Iran will finally relent after the pivotal elections are held in the US.

"I think the war's going to end immediately after the election because they can't hold out any longer," Trump said.

The president at the outset of the war said it would last a matter of weeks. The war is now in its seventh month. (AP)