The United States ambassador in London has said he is confident that Britain will continue to enjoy a "vibrant" trade relationship with the USA after Brexit, despite President Barack Obama's warning that the UK would go to the "back of the queue" for a trade deal.
With the TTIP trade agreement between the US and EU apparently mired in delays, Matthew Barzun said that America would not be "waiting" for deals to be struck but would carry on building economic ties with close partners like the UK.
The ambassador, whose time in London draws to an end as Donald Trump takes office in January, said he was "losing no sleep" about the survival of the special relationship between the UK and US, which was "really strong now and will continue to be strong".
Ever the diplomat, Mr Barzun declined to make any comment about his expectations for a Trump presidency when he spoke with the Press Association following a question and answer session with young people at Twitter's UK HQ in London, saying only that Mr Obama had asked all ambassadors to do everything they could to ensure that the transition to the new administration "goes as smoothly as it can do".
And he kept his silence over the president-elect's surprise suggestion that Nigel Farage would make a great head of the UK embassy in Washington, telling PA: "I will leave that to Her Majesty's Government to decide."
But he said that, after a turbulent year in which electorates on both sides of the Atlantic had expressed "unease" about the direction the world is going, it was up to elected leaders to stand up for the organisations - many of them developed by the US and UK working together - which have provided a framework for free trade and collective security since the Second World War.
Asked whether Europeans could rely on the US to remain at the heart of Nato and at the heart of the free trading system after both were called into question during the presidential election campaign, Mr Barzun agreed that 2016 had seen "unease and divisions ... on both sides of the Atlantic and both sides of the political spectrum".
"Big groups of my fellow citizens and citizens over here in this country feel disconnected from the systems that we have built up," he said. "FDR (US President Franklin Roosevelt) and Sir Winston Churchill not only won a war together but built this post-war infrastructure.
"These systems and these organisations aren't perfect, but they really work and they've helped us during the Cold War, they've helped us after that and I think the job of our elected leaders on both sides of the Atlantic and leaders in general - whether it's business leaders or folks in the media - is to engage and try to listen and help people feel connected and make sure these systems are working for everybody and not just a few."
Mr Trump's decision to call nine other world leaders before speaking to Theresa May following his election victory raised eyebrows in London over the future of the special relationship.
But Mr Barzun dismissed any suggestion that the cherished link was in decline.
"I think the special relationship is vibrant and vital," he said.
"In the 70 years since Sir Winston coined that phrase, at least once a year someone declares it dead or dying, and it isn't.
"It lives between our government leaders, it exists within the 24,000 official visit-nights that we host through our embassy here in London, and that's not even counting all the economic ties, the student exchanges, the tourism of four million travellers from the UK going to America, four million travellers from America going to the UK."
Even after Brexit, the UK would remain "an incredibly important partner" in international forums like the UN Security Council, G7, G20 and Nato, he said.
And on trade, he said: "The United States and the United Kingdom have this vibrant trading relationship that's been going on for decades. It continues today. We are not waiting, we are doing the hard, simple, worthwhile work of building economic ties between our two countries.
"That I'm confident will continue."
An early supporter of Obama, who recalled watching the young senator addressing audiences of a dozen in rural backwaters as he sought the Democrat nomination for the presidency, Mr Barzun headed the US embassy in Sweden for almost two years before moving to London. There, he has hosted a total of 36,600 people in the grandeur of the ambassador's official residence of Winfield House in Regent's Park.
But he said it was not the sparkling receptions and A-list guests he would remember most fondly from his time in Britain, but his trips to 125 towns and cities around the UK, including visits to 163 schools to speak with 20,040 sixth-formers about their hopes, dreams and worries for the future.
There was "absolutely affection" for the US among these British teenagers but also sharp criticisms of America and its impact on the world.
But after a year of polarised politics on both sides of the Atlantic, he said his school talks showed him that "our democracies demand of one another that we are able to disagree and we are able to discuss and do so in an atmosphere of decency - that's something I have experienced as I have been so warmly welcomed by the British people. We've been able to talk about areas where we agree and where we disagree and we are stronger for it."
Discussing the future of the special relationship, Mr Barzun added: "Sometimes we get tricked into thinking that we do hard things together around the world - like combating Ebola, like the work we did together on the Iran deal - because we are close friends. There's certainly a truth to that, but I think what is more powerful is that we are friends because we have done hard things together.
"There are hard things we are confronting now and in the future. My hope is that ... the generations that come after will be inspired by the generations that came before and what we are doing today and they will continue that hard and important work together."