United Kingdom, April 8 -- Jimmy Kimmel has slammed Donald Trump for his aggressive rhetoric on Iran.

The 58-year-old talk show host is a vocal critic of the US President and used his opening monologue on Tuesday's (07.04.26) of Jimmy Kimmel Live! to take aim at Trump's threat that "a whole civilisation will die tonight" unless the Gulf nation agreed to re-open the Strait of Hormuz.

Kimmel said: "Probably the most dangerous episode of The Celebrity President yet today: It was D-day. In this case, the 'd' stands for 'dementia', but it was D-Day today.

"We're coming to you from Los Angeles where the local time's just after 5pm, which was Trump's deadline for Iran to quote, 'Open the effing strait or you'll be living in hell.' He gave a h...