WASHINGTON, April 7 -- Donald Trump doubled down yesterdayon his threat to wreck Iran's civilian infrastructure, warning US forces could destroy every bridge and power plant in the country within four hours and that a truce proposal from international mediators was not yet enough.

Five weeks into the Middle East war triggered by a joint US-Israeli air assault on Tehran, the US leader has demanded that Iran reopen the Strait of Hormuz to international shipping by midnight GMT on Tuesday, or face a newly devastating round of bombing.

Both Trump and Iran have said that a proposal touted by international mediators for a 45-day ceasefire is not yet ready, and in a Washington press conference, the US president dialled up his warlike rhetoric ...