After surging above $100 a barrel on Monday, oil falls closer to $90 - but remains above pre-war levels. Trump also says he will hit Iran "twenty times harder" if they block the Straits of Hormuz.

"Additionally, we will take out easily destroyable targets that will make it virtually impossible for Iran to ever be built back, as a Nation, again — Death, Fire, and Fury will reign upon them — But ...