The Government has slapped down comments from Boris Johnson that the UK is expected to begin formal talks to leave the European Union by "the early part of next year".
The Foreign Secretary told Sky News that ministers were working towards triggering Article 50 of the EU treaties in the first part of 2017.
But a number 10 spokesperson distanced the Government from Mr Johnson's comments.
The spokesman said: "The Government's position has not changed - we will not trigger Article 50 before the end of 2016 and we are using this time to prepare for the negotiations."
ITV News Political Correspondent Libby Wiener tweeted that government sources viewed Mr Johnson's comments as "not helpful".
The Foreign Secretary was speaking in New York where he has been attending the United Nations.
He suggested the Article 50 discussions could be wrapped up before the two-year deadline.
After that, Britain will have two years to negotiate a deal.
But Prime Minister Theresa May has previously said that she will not be rushed into starting the process.