Washington(CNN) Kim Darroch, the former United Kingdom ambassador to the United States, said the Trump administration was "set upon an act of diplomatic vandalism" in its decision to abandon the Iran nuclear deal, the Mail On Sunday reported Saturday, citing leaked cables.
The report comes following news last week that Darroch sent diplomatic cables describing President Donald Trump as "inept," "insecure" and "incompetent," a UK government official confirmed to CNN. Darroch has since resigned.
According to the Mail On Sunday, the former ambassador said Trump seemed to be discarding the Iran nuclear deal for "personality reasons," as the deal had been agreed to by former President Barack Obama. The paper also reported that Darroch hinted at discord brewing between Trump's closest aides and said the White House had failed to produce a "day-after" plan on how to handle the aftermath of withdrawing from the deal.
CNN has not seen the leaked cables and cannot confirm their contents.
The White House told CNN it has no comment on the story.
Trump said Monday that the White House would no longer deal with Darroch, and the UK Foreign Office announced Darroch's resignation Wednesday. The former ambassador made his decision to step down after seeing that Boris Johnson, the current frontrunner to replace Theresa May as British Prime Minister, had refused to support him during Tuesday night's leadership debate, a British government official confirmed to CNN.
A UK Foreign Office spokesman told CNN on Saturday that whoever leaked the cables "should face the consequences of their actions."
"It's not news that the US and UK differ in how to ensure Iran is never able to acquire a nuclear weapon; but this does underline that we do not shy away from talking about our differences and working together," the spokesman said. "That is true of the current tensions in the Gulf where we, the UK, are in close contact with our American and European allies to de-escalate the situation."
Police in the UK have opened a criminal investigation into the leaked diplomatic cables that led to Darroch's departure. Metropolitan Police Assistant Commissioner Neil Basu said Friday that there is a "clear public interest in bringing the person or people responsible to justice."
Basu's statement caused concern over press freedom in the UK after he controversially warned journalists that publishing leaked government documents may lead to a criminal prosecution.
However on Saturday the assistant commissioner released an updated statement, reiterating that the police force "respects the rights of the media and has no intention of seeking to prevent editors from publishing stories in the public interest in a liberal democracy."
Meanwhile, Isabel Oakeshott -- the journalist behind the Mail on Sunday stories based on the leaked diplomatic telegrams -- confirmed on Twitter that she is dating the chairman of the Brexit Party, but adding that "he had nothing to with my story."
He "has never seen the cables and doesn't know the identity of the source," Oakeshott wrote in response to newspaper reports that she was dating Richard Tice.
"So what? It is not a secret," she wrote Sunday.
Tice, for his part, also rejected suggestions he was angling to replace Darroch.
"Conspiracy theorists who think I want US Ambassador job totally wrong. Ridiculous suggestion! But other senior pro Brexit businessperson [sic] would do great job promoting U.K. & securing quick trade deal," he tweeted.
After Trump pulled out of the Iran deal in 2018, the US imposed new sanctions that have crippled the Iranian economy, which now exports less than half of the oil it did before the new round of sanctions.
On the campaign trail, Trump repeatedly denounced the Iranian nuclear agreement as "the worst deal ever."
But at the time the US withdrew from the Iran deal, senior Trump administration officials -- including Secretary of State Mike Pompeo and the Director of National Intelligence Dan Coats -- said Iran was adhering to its commitments under the deal.
Tensions between the US and Iran have been escalating in recent weeks, which eventually led to Tehran announcing it would no longer comply with the nuclear deal and started to increase uranium enrichment beyond the purity threshold it agreed with America and five other nations in 2015.
Earlier this week, Trump tweeted that Iran "has long been secretly 'enriching'," a claim that has been contradicted by the International Atomic Energy Agency, whose monitors were tasked with ensuring that Iran was complying with the terms of the 2015 deal, as well as by independent experts and by Trump's own top intelligence officials.
Clarification: This story has been updated to note that the story was published by the Mail On Sunday, the sister paper of the Daily Mail that publishes on Sunday.