Marathon through the night political negotiations in Belfast have failed to produce an agreement to deal with unresolved peace process issues in Northern Ireland.
Seven hours of intensive talks involving Stormont's five Executive parties chaired by former US diplomat Dr Richard Haass ended around 4am without the pre-Christmas agreement the one-time White House special envoy to the region desired.
Dr Haass, who has an end-of-year deadline to find consensus on disputes over flags, parades and the legacy of the Troubles, will now fly back for Christmas in the United States.
But he said he and talks co-chairwoman Dr Meghan O'Sullivan, a US foreign affairs expert, will consider returning next weekend if they believe an eleventh hour deal could yet be struck.
They will send questions to the parties from the US and, based on the answers, will produce another draft set of proposals - the fifth version created.
If the reaction from the parties to that new document suggests further progress can be made, Dr Haass said he and Dr O'Sullivan would fly back.
Emerging from the meeting at the Stormont Hotel, Dr Haass insisted the process was not dead.
"I am not in the business of doing post mortems here because the patient is still alive," he said.
Dr Haass said there continued to be "significant differences and divisions" among the parties on all three issues being discussed.
While some progress has been made on parades and dealing with the past, there appears no prospect of an imminent deal on flags.
"The work done on flags is quite disappointing by any measure," said Dr Haass.
"But the other two areas have been, I believe, quite impressive and I believe it would be a real shame not to be able to turn that work into a reality."
He added: " We would like to think there is reason to return."
Appointed in the summer by Democratic Unionist First Minister Peter Robinson and Sinn Fein Deputy First Minister Martin McGuinness to oversee the talks initiative, Dr Haass has flown back and forth to the region on numerous occasions, working up to a period of arduous negotiations over the last two weeks.
A crunch plenary meeting had been due to commence at 11am yesterday, but it did not get under way until just before 9pm last night, with the politicians having spent most of the day assessing Dr Haass's fourth draft document.
The exchanges ran through the night, with Dr Haass pressing for a breakthrough before he had to travel to Dublin to catch a morning flight back across the Atlantic.
After the talks broke up without success, he said:
"Let me be clear about this - we don't have an agreement, (but) in no way have we given up the possibility of still reaching an agreement before the end of the year.
"We are not going to be able to put it underneath anyone's Christmas tree but we still have a week and if there is reason to return - I think we will have the answer to that question when we get the responses to a new draft that we will produce over the next few days - then both of us are willing to come back here, fly back here and give it one last push."
It is understood the politicians have effectively conceded that another forum will need to be established to examine issues around flags over a longer time frame.
But if the fifth draft secures a breakthrough on the two other areas, it should pave the way for a replacement for the Parades Commission to rule on contentious marches by unionist and nationalist groups, and on a new mechanism to oversee dealing with the legacy of the past - potentially one offering limited immunity from prosecution to those who co-operate.
Dr Haass made clear that work commitments meant neither he or Dr O'Sullivan would be able to engage in the process beyond the end of the year.
After the night's meeting, DUP negotiator Jeffrey Donaldson said he felt the outstanding problems could be fixed.
"Obviously I think everyone is disappointed that we are not having an agreement at this stage," said the Lagan Valley MP.
"But we have to be realistic - there remain significant issues of difference across all three areas that were under negotiation.
"I think with further effort we are capable of closing the gap but it just didn't happen tonight."
Sinn Fein's talks spokesman Gerry Kelly said the party's negotiators had been mandated by its ruling executive to try to secure agreement in the meeting.
"We are disappointed that we weren't able to do that," he said.
"Probably more important is that people watching this will be more disappointed if we can't bring this to some sort of conclusion in the few next few days and phases.
"When it came to a deal, I think we could have done it, (but) we didn't manage to do it.
"Richard Haass said he may come back, we'll see what that brings."
Ulster Unionist Party leader Mike Nesbitt expressed optimism as he left the talks.
"The deadline is next Tuesday, it wasn't today," he insisted.
"We didn't get there tonight but I think we did get real in terms of a better understanding of where everybody's bottom line is, and why they are taking the positions they are taking.
"So I remain optimistic - there's a lot that I think we can get over the line over the next few days and by next Tuesday, who knows, maybe we will have an agreement."
SDLP negotiator Alex Attwood said: "W e said to Richard Haass and Meghan O'Sullivan 'A safe home over the Atlantic and we will see you next weekend back in Belfast', because whilst we haven't got a Christmas Eve deal we can still achieve a New Year's Eve deal and that is the purpose of the next week."
Alliance party deputy leader Naomi Long said while the process was not dead it was on "life support".
"We need to go and we need to reflect on the conversations we have had and we need to find ways of accommodating each other in this process," she added.
"Because ultimately, if we can accommodate each other in this process, we can go out with confidence and ask people in our community to accommodate each other in their communities. And that is hugely important in terms of transforming this landscape."
Shadow Northern Ireland secretary Ivan Lewis said: "The lack of an agreement before Christmas is clearly disappointing.
"The priority now is for all Northern Ireland's political leaders to demonstrate their continued commitment to this process by asking Richard Haass and Meghan O'Sullivan to return at the earliest opportunity.
"Now is also the time for the UK and Irish Governments to step up to the plate and use their influence to help put the process back on track.
"The Haass talks offer the best hope for dealing with contentious issues such as the past, parades and flags, which continue to be obstacles to the development of a shared future for Northern Ireland.
"The vast majority of people in Northern Ireland want to see progress on these issues.
"That will require politicians to show the leadership which is necessary to balance strong convictions with difficult but necessary compromises."
Tanaiste Eamon Gilmore, the Republic' s Minister for Foreign Affairs, said he has thanked Mr Haass and Dr O'Sullivan for their guidance of the process to date, and their willingness to return to Northern Ireland later this week if they judge that there may be the basis for agreement.
"At this point I would ask the five parties of the NI Executive to see through the very important work they have engaged in over recent months on the difficult issues of parades, flags and dealing with the past," he said.
"The next few days are an important opportunity for reflection following an intensive period for all concerned.
"The Irish Government stands ready to support the process in any way possible. Our objective, which I know we share with all of the parties in the Northern Ireland Executive and with the British Government, is to see Northern Ireland make further progress towards reconciliation.
"An agreement on these issues is essential to reaching that objective."