Ted Malloch on UK-US trade under Trump after Brexit
12 January 2017 Last updated at 14:44 GMT
President Obama's claim that the UK would be at the back of the queue for a new US trade deal if it left the EU has been challenged.
Ted Malloch, who is expected to be confirmed as Donald Trump's ambassador to the EU, said: "The UK is now at the front of the queue."
Earlier in his Daily Politics interview, he confirmed he had met Mr Trump about the role, but told presenter Andrew Neil, "It can't be confirmed until it comes from his mouth."