Donald Trump has said Britain should embrace a no-deal Brexit if Brussels refuses to meet its demands.
The US president said the UK should "walk away" from talks and refuse to pay the £39 billion divorce bill if requests are not met.
And he told the Sunday Times it was a "mistake" not to involve Brexit Party leader Mr Farage in negotiations, saying he has a "lot to offer" and is someone he likes "a lot".
"He is a very smart person. They won't bring him in. Think how well they would do if they did. They just haven't figured that out yet," he said.
Trump also vowed to "go all out" to secure a free trade deal between the UK and US within months of Britain leaving the EU.
The president added that he would back Boris Johnson to become the next Prime Minister, and defying diplomatic norms, said he would have to get "to know" Jeremy Corbyn before authorising the sharing of highly sensitive US intelligence.
He hinted that he "may" meet with Mr Johnson during his UK trip.
The US politician is set to arrive on UK soil this morning for a three-day state visit, and has a packed schedule ahead.
Among his engagements are a meeting and state banquet with the Queen, plus tea and a photo opportunity with Prince Charles and Camilla the Duchess of Cornwall.
He said he expected his visit to be "very important" and "very interesting" as he left the White House on Sunday evening.