Ambassador Johnson hailed the historic agreement and said there would be “so many new opportunities” for the UK and the US to pursue in the future. He posted a clip of the Prime Minister’s speech on Twitter, and wrote: “Congratulations to the UK and EU on striking a Brexit deal.”
He said there would be “so many new opportunities to pursue” between London and Washington.
Ambassador Johnson’s tweet came just hours after the Prime Minister announced a free trade agreement had been sealed with Brussels.
Negotiators worked through the night to hammer out the final points on the much-anticipated deal, which came just eight days before the UK leaves the transition period.
US President Trump has in the past said Washington wanted a big post-Brexit trade deal with London.
Ambassador Johnson recently offered an update on trade talks between Britain and America.
On December 17 he shared a screengrab of an Express.co.uk poll which showed readers would rather see a UK-US trade deal than a UK-EU pact.
He told his followers: “We’re going to get this done for YOU!”
His pledge came a day after the UK and the US signed a customs agreement.
The Ambassador shared a photo of himself signing the agreement alongside Jesse Norman, financial secretary to the Treasury.
Mr Trump’s man in Britain said the deal would “ensure our important crime-fighting will continue uninterrupted”.
Under the terms of the agreement, London and Washington agreed to exchange information and evidence to assist the two nations in the enforcement of customs laws, including duty evasion, trafficking, proliferation, money laundering and terrorism-related activities.
Ambassador Johnson said the signing of the agreement would mean continued cooperation to stop the illegal flow of weapons and drugs between the two nations.
And in early December he met with the UK’s International Trade Secretary Liz Truss to discuss the ongoing trade talks.
Ambassador Johnson said both sides were “working hard every day to get a great FTA”.
Last week the US trade representative, Robert Lighthizer, said both nations were close to reaching an agreement on reducing trade tariffs.
Mr Lighthizer, who is a member of Mr Trump’s outgoing administration, said he was discussing the possible lifting of US levies on goods including Scotch whisky,
He suggested an agreement on tariffs could appear in the coming weeks.
He told the BBC: “I’m hopeful we can get some kind of an agreement out, you know, we don’t have a lot of time left.”
President Trump is due to leave the Oval Office on January 20, as President-elect Joe Biden is sworn in.
At around 3pm on Christmas Eve Mr Johnson’s office announced a trade deal had been struck with Brussels.
Shortly afterwards, the Prime Minister made a live televised speech, saying: “We have taken back control of our laws and our destiny.
“We have taken back control of every jot and tittle of our regulation in a way that is complete and unfettered.”
His announcement came just eight days before the UK leaves the Brexit transition period.