The Foreign Secretary says the Government expects to invoke Article 50, which begins the process to leave the EU, by early 2017.
Boris Johnson has said the process of leaving the EU does not need to take two years once Article 50 is invoked.
Speaking to Sky News in New York, the Foreign Secretary said he expected Article 50 – the formal mechanism for beginning the exit from the Union – to be invoked early next year.
He also said Britain would “take back control” with a global free trade package and a deal on financial services.
Once Britain invokes Article 50 and informs the European Council it is leaving, it has a maximum of two years to negotiate the terms of its withdrawal.
Extra time could be granted, but only if the other 27 EU states agreed.
But Mr Johnson said it was possible the process of leaving could be completed quicker than some expect.
“By the early part of next year you will see an Article 50 letter which we will invoke, and in that letter I am sure we will be setting out some parameters for how we propose to take this forward,” said the Foreign Secretary.
“You invoke Article 50 in the early part of next year (and) you have two years to pull it off. I don’t actually think you need to spend the full two years but let’s see how we go.
“We are going to benefit from fantastic opportunities for free trade with our friends in the EU.
“Not only do we buy more German cars that anybody else, we drink more Italian wine than everyone else – they’re not going to put that at risk.”
His comments came as PM Theresa May sought to smooth the Brexit process, telling the head of the European Parliament she wanted Britain to have a “close relationship” with the EU.
Mr Johnson also revealed more details about the Government’s Brexit plan and hinted there could be free-movement sweeteners offered to non-EU countries as part of any trade deal, such as more visas and work permits.
Sky News Foreign Affairs Editor Sam Kiley said: “He first said such an idea was ‘cobblers’ but quickly backtracked when it was pointed out that Australia’s Foreign Minister told Sky News that a free-trade deal with the UK would mean more visas for Australians to live and work there.