Boris Johnson's treatment by Luxembourg's prime minister is a reminder of why the UK wants to leave the EU, the US ambassador has said.
Woody Johnson said that Brits had "built the greatest empire" and "held off the Nazis" so they "don't need a lecture from anybody on how to run their country... and that includes Brussels".
"We stand with the people of the UK and we always will," he said, according to the Telegraph.
It comes after Luxembourg's PM Xavier Bettel was accused of deliberately embarrassing the UK, after trying to hold a press conference in a street full of anti-Brexit protesters.
The PM pulled out while Mr Bettel posed for cameras next to his empty podium.
The US ambassador praised Mr Johnson's handling of the situation, insisting that "he knew he was walking into a trap".
He said: "I thought the people in Luxembourg accomplished something that maybe even Boris couldn't accomplish - show this is not where (the British) want to be, over there, when they treat us like that - your Prime Minister."
Addressing a Conservative Foreign Council lunch at the Carlton Club, the ambassador said the Trump administration believes the UK is on the cusp of "a new golden era".
Meanwhile, Mr Bettel's "empty chairing" of Mr Johnson appeared to cause unease in Brussels and Berlin on Tuesday.
Norbert Rottgen, an ally of Angela Merkel, wrote on Twitter: "Xavier Bettel's speech yesterday did not serve the European cause.
"His public venting ignored a deal is still in everyone's interest.
"Even without a deal there will be a post-Brexit life, which means that right now everyone needs to behave in a way that avoids animosity."
Ambassador Johnson insisted that Britain could have agreements with both Washington and Brussels.
He said: “The US cannot wait to do a deal. Together with Britain, we are going to show the world how free and fair trade can promote peace and prosperity around the world.
"So it’s full steam ahead... the minute the UK is out, America is in.”
