Britain's now-former ambassador to Washington has said he believes U.S. President Donald Trump withdrew from the 2015 Iranian nuclear deal because it was associated with predecessor Barack Obama, leaked documents show.
"The administration is set upon an act of diplomatic vandalism, seemingly for ideological and personality reasons -- it was Obama's deal," Kim Darroch wrote in a diplomatic cable in May 2018, according to documents revealed on July 14.
The cable was part of a second batch of leaked documents published by Britain's Mail On Sunday newspaper.
U.K. police are hunting the culprits behind the leak while warning media organizations that publishing the documents "could also constitute a criminal offense."
British officials have said they have no evidence that hacking was involved in the documents' release and that the culprit is likely to be found among politicians or civil servants in London.
A spokesman for the Mail on Sunday said it was continuing to publish details from the leaks because it contained "important information about how Britain tried, but failed, to stop President Trump abandoning the Iran nuclear deal."
In the first batch, dating from 2017 to the present, Darroch said the U.S. administration was "diplomatically clumsy and inept" and would not likely become "substantially more normal; less dysfunctional; less unpredictable; less faction riven."
Trump responded by calling Darroch "stupid" and "wacky" and said he would no longer have any contact with the British envoy.
Darroch resigned days later, saying in a letter on July 10 that although his posting was due to be completed at the end of the year, he believed that "in the current circumstances the responsible course is to allow the appointment of a new ambassador."
Darroch criticized the U.S. administration for what he called a lack of long-term strategy.
"They can't articulate any 'day-after' strategy; and contacts with State Department this morning suggest no sort of plan for reaching out to partners and allies, whether in Europe or the region," Darroch wrote in 2018.
The nuclear deal -- which provided Iran with relief from sanctions in return for curbs on its nuclear programs -- was agreed during Obama's term in office. The pullout has led to a surge in tensions between Washington and Tehran over the past year.