Leaked diplomatic cables reveal that Britain's ambassador to the United States regards President Trump's administration as inept, hobbled by infighting, and unlikely to improve.

The memos published in the Mail on Sunday newspaper contain highly critical comments from Ambassador Kim Darroch about the current state of Mr. Trump's government, providing a rare look at how a senior British diplomat views the government of Britain's closest ally.

"We don't really believe this administration is going to become substantially more normal; less dysfunctional; less unpredictable; less faction riven; less diplomatically clumsy and inept," Darroch wrote in one of a series of leaked documents covering the period from 2017 to the present.

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Britain's Foreign Office did not challenge the authenticity of the leaked documents. It called the leak "mischievous behavior" and said the public expects diplomats to provide honest assessments of the politics in the countries where they are posted.

In a statement provided to CBS News, the Foreign Office said:

The British public would expect our Ambassadors to provide Ministers with an honest, unvarnished assessment of the politics in their country. Their views are not necessarily the views of Ministers or indeed the government. But we pay them to be candid. Just as the US Ambassador here will send back his reading of Westminster politics and personalities. Of course we would expect such advice to be handled by Ministers and civil servants in the right way and it's important that our Ambassadors can offer their advice and for it remain confidential. Our team in Washington have strong relations with the White House and no doubt that these will withstand such mischievous behaviour.

Justice Secretary David Gauke called the leak "disgraceful" but said Britain "should expect our ambassadors to tell the truth, as they see it."

The memos also characterized Mr. Trump's policy on Iran as "incoherent, chaotic." Mr. Trump has frustrated European allies by withdrawing the United States from a complex deal designed to prevent Tehran from obtaining nuclear weapons and has seemed in recent weeks to be on the verge of armed conflict with Iran.

The ambassador said he did not believe Mr. Trump's public explanation for calling off a planned military strike against Iran last month.

Darroch said there are doubts about whether the White House "will ever look competent" and that the only way to communicate with the president is by being simple and blunt.

He said that while Trump had been "dazzled" by British pageantry on a state visit hosted by Queen Elizabeth II in June, the successful visit would not lead to a fundamental shift in Trump's priorities.

"This is still the land of America First," he wrote.

Darroch expressed a more measured view of the relationship between the two countries in an interview with CBS News chief Washington correspondent Major Garrett on "The Takeout" podcast last fall. Darroch said then that while the U.K. had a good relationship with the Trump administration, British leaders also recognized the need to "look at Twitter a bit more often than we used to."

"There are times when things happen unexpectedly. That's not unique to this administration," Darroch said.

"My interpretation of what the president says is that he believes strongly in pursuing American interests."

Darroch's unvarnished views in the leaked diplomatic cables may lead to some awkwardness, especially since Trump said shortly after his election in 2016 that Brexiteer Nigel Farage would make an excellent British ambassador to the United States.

Trump has not hesitated to inject himself into Britain's political fray, repeatedly criticizing Prime Minister Theresa May's Brexit negotiating strategy and praising both Farage and former Foreign Secretary Boris Johnson, a strong contender to become the next prime minister.