Mike Pompeo, the US secretary of state, threatened Iran with the "strongest sanctions in history" and vowed to "crush" the regime's proxies around the world on Monday, sparking a furious response from Tehran.

Mr Pompeo also called for a new nuclear treaty with Iran to replace the Obama-era deal that Donald Trump withdrew from earlier this month.

But the top US diplomat issued a list of 12 requirements for such a deal, many of which Iran would be unlikely to agree to.

He said the US would apply "unprecedented financial pressure" on Iran and send teams of specialists to allies around the world to explain US policy.

Mr Pompeo said if Iran makes "major changes" the US was willing to lift all sanctions.