The fate of the Iran nuclear deal remains in the balance despite efforts by the leaders of France and Germany and now Britain's Foreign Secretary, to persuade the US not to pull out at the end of the week.
On Sunday French President Emmanuel Macron told German online Spiegel, if Trump were to simply withdraw from the deal "that would mean opening Pandora's box, it could mean war." But, he added "I don't believe that Donald Trump wants war."
Meanwhile Iranian President Hassan Rouhani appeared on Iranian state television warning the US it will face "historic regret" if Donald Trump scraps the nuclear agreement.
Tehran insists its nuclear programme is entirely peaceful and says it considers the deal non-renegotiable.
It signed it back in 2015 agreeing to curb its nuclear programme in return for the lifting of crippling sanctions.
Trump has strongly criticised the agreement, calling it "insane" and wants flaws in the deal fixed before a May 12 deadline.