Mr Johnson also revealed more details about the British government's Brexit plan
Boris Johnson has said that the process of leaving the EU does not need to take two years once Article 50 is invoked.
Speaking in New York, the Foreign Secretary said he expected Article 50 would be invoked in early 2017 and 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 the EU, 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.
Speaking in New York where he has been attending the United Nations, Mr Johnson told Sky News: "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.
"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 lets 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."
Mr Johnson also revealed more details about the British government's Brexit plan and hinted there could be free-movement sweeteners offered to non-EU countries as part any trade deal, such as more visas and work permits.
Mr Johnson's suggestion that Britain would begin Brexit in early 2017 echoed comments made on Saturday by Donald Tusk.
The EU Council president let slip at a summit in Bratislava that Theresa May told him she wanted to invoke Article 50 in either January or February next year.
Downing Street later insisted that Mr Tusk's comments were only his "interpretation" of the meeting.