The British government has launched an investigation to find the mole who leaked confidential memos from Britain's ambassador to the United States in which he described President Donald Trump's administration "dysfunctional" and "inept". Ambassador Sir Kim Darroch reportedly said Mr Trump’s presidency could “crash and burn” and “end in disgrace” in the cache of secret cables and briefing notes sent back to Britain which were leaked to UK newspaper the Mail On Sunday. In a bid to curb a diplomatic row, Prime Minister Theresa May's spokesperson said she had "full faith" in Sir Darroch, a long-serving diplomat, although she didn't agree with his characterisation of the Trump administration. Officials believe the mole will be found among British politicians or officials, rather than overseas. "I've seen nothing to suggest hostile state actors were involved," said Mrs May's spokesman, James Slack. He said ambassadors were hired to provide "honest, unvarnished assessments" of politics in the countries where they served, which didn't necessarily reflect the views of the British government. In the leaked cables Sir Darroch called the Trump administration's policy toward Iran "incoherent, chaotic" and said there were doubts about whether the White House "will ever look competent." "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," one missive said. The cables cover a period from 2017 to recent weeks. After the cables were published, Mr Trump said the ambassador "has not served the UK well, I can tell you that." "We are not big fans of that man," he added. British Foreign Secretary Jeremy Hunt said Monday that the ability to communicate frankly was "fundamental" to diplomacy. International Trade Secretary Liam Fox, who is meeting US officials in Washington, called the leak "malicious." "I think it is unconscionable that any professional person in either politics of the civil service can behave in this way," he said On Monday, Britain's Trade Minister Liam Fox, who is on a visit to Washington, said he would apologise to the president's daughter Ivanka Trump who he is due to meet during his trip. "I will be apologising for the fact that either our civil service or elements of our political class have not lived up to the expectations that either we have or the United States has about their behaviour, which in this particular case has lapsed in a most extraordinary and unacceptable way," he said. "Malicious leaks of this nature are unprofessional, unethical and unpatriotic and can actually lead to a damage to that relationship which can therefore affect our wider security interest," he told BBC radio. One of the memos sent after Mr Trump's UK visit said the president and his team had been “dazzled” by the experience but warned Britain might not remain “flavour of the month” because “this is still the land of America First”. He reportedly wrote that the “vicious infighting and chaos” inside the White House – widely reported in the US but dismissed by Mr Trump as “fake news” – was “mostly true”. Sir Darroch is one of Britain’s most experienced diplomats whose posting in Washington DC began in January, 2016, prior to Mr Trump winning the presidency.