Donald Trump has warned that the US will hit Iran “very fast and very hard” if it takes retaliatory action after the assassination of the terror chief Qassem Soleimani.

The US president said that the military has identified 52 Iranian targets, including some “very high level” cultural sites, which he said the will be hit if Iran launches attacks against the US. Iran said that targeting cultural sites would represent a “war crime”.

The intensifying rhetoric came amid mounting concern about the threat of war as Dominic Raab, the foreign secretary, warned that Islamic State could “exploit the vacuum” if the US is expelled from Iraq.

US officials are preparing for retaliatory attacks by Iran against American and British interests in the Middle East, South America and Africa

He said that Iran could still “come in from out of the international cold” and that the “opportunity is