Speaking to CNBC ahead of the triggering of Article 50, the Brexiteer accused the President of the European Commission Jean-Claude Juncker of standing in the way.
He said: “Quite honestly, if the British Government went to Trump today and said right, let's crack on, I think that certainly by the end of this year if not a considerable time before, a trade deal could be done.
"But the problem is we are not allowed to because Mr Juncker says we can't do it until we have left the European Union.
Nigel Farage claimed Donald Trump would give the UK a trade deal by the end of the year
The White House is very positive about the Anglo-American relationship in terms of trade, in terms of security, in terms of defence
“What we can do, we can begin the initial discussions and I think the sooner we take the attitude in this country that we’re leaving political union with Europe and rejoining the world the better.”
Mr Farage claimed American officials looked at the UK with “incredulity” for being subject to the European Union.
He said: “I have every reason to believe that [the UK could secure a deal] – the White House is very positive about the Anglo-American relationship in terms of trade, in terms of security, in terms of defence.
“For many in Washington they look on with incredulity that a British Prime Minister is told by a Brussels-based bureaucrat that we are not allowed to sign a deal.”
Brexit day LIVE: images from around the country as Britain invokes Article 50 Wed, March 29, 2017
The country reacts as Theresa May officially invokes Article 50, and begins the process of Britain leaving the European Union
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Prime Minister Theresa May announces in the House of Commons that she has triggered Article 50, starting a two-year countdown to the UK leaving the EU
Nigel Farage jabbed at Jean-Claude Juncker in his rant before the triggering of Article 50
He added: “We are about to become – [with a] two-year wait perhaps – a self-governing, independent, democratic, normal nation. Hooray.”
The comments come as Article 50 is set to be triggered on Wednesday, kicking off a two-year negotiation period.
Theresa May is expected to promise in a statement to MPs: "When I sit around the negotiating table in the months ahead, I will represent every person in the whole United Kingdom – young and old, rich and poor, city, town, country and all the villages and hamlets in between, yes, those EU nationals who have made this country their home.
"It is my fierce determination to get the right deal for every single person in this country.
"For as we face the opportunities ahead of us on this momentous journey, our shared values, interests and ambitions can – and must – bring us together.”