Donald Trump abandoned the Iran nuclear deal to spite Barack Obama, according to a leaked memo written by the UK's former ambassador to the US.
Sir Kim Darroch described the move as an act of "diplomatic vandalism", according to the Mail on Sunday.
It says the memo was written after the then Foreign Secretary Boris Johnson appealed to the US in 2018 to stick with the nuclear deal.
Under that agreement Iran agreed to limit its sensitive nuclear activities.
It would also allow in international inspectors in return for the lifting of crippling economic sanctions.
However, President Trump did not think that the deal went far enough.
The newspaper reports that after Mr Johnson returned to the UK from the US, Sir Kim wrote that President Trump appeared to be abandoning the nuclear deal for "personality reasons" because the pact had been agreed by his predecessor, Barack Obama.