Boris Johnson has played down the chances of a “New York breakthrough” on Brexit during discussions with key EU leaders at the United Nations.
The Prime Minister is set to meet with Angela Merkel, Emmanuel Macron, Donald Tusk and Leo Varadkar during the annual General Assembly in the States.
Mr Johnson will this week discuss his proposals for a new Brexit deal as the October 31 deadline looms.
He celebrated a “great deal of progress” having been made but sought to limit expectations when speaking to reporters on board the RAF Voyager on the way to JFK airport.
“There will be discussions about Brexit. I would caution you all not to think that this is not going to be the moment… there will be no New York…” he said.
“There might be, but I don’t wish to elevate excessively the belief that there will be a New York breakthrough.
“We will be pushing ahead but there is still work to be done.”
He said it was “very encouraging” to hear EU chief Jean-Claude Juncker say he is not wedded to the mechanisms of the Irish backstop, the emergency measure to prevent a hard border returning to the island.
He also said he has “seen interest” in treating the whole island as a single zone for sanitary and phytosanitary purposes but warned it is “early days” and “there are clearly still gaps and still difficulties”.
And on his current outlook, he said: “It would be still fair to say I’m in the same position I was. I think cautiously optimistic would be about right.”
The PM will meet with European Council president Mr Tusk on Monday, before meeting German Chancellor Ms Merkel and French President Mr Macron.
Mr Johnson will meet with his Irish counterpart Mr Varadkar the following day.
The Taoiseach’s deputy, Simon Coveney, has warned that a “wide gap” remains between Mr Johnson and the EU on a new Brexit deal.
The Prime Minister is also awaiting the judgement from the Supreme Court over the legality of his prorogation of Parliament but this will not be handed down on Monday morning, with a further announcement on timing expected around lunchtime.