The former US diplomat tasked with forging a political agreement on unresolved peace process issues in Northern Ireland has pledged to leave no stone unturned in a bid to secure a deal before Christmas Eve.
Dr Richard Haass said the next 72 hours would be "crunch time" in negotiations to resolve disputes over parades, flags and the legacy of the past.
The former White House envoy to the region, who is chairing talks between the five parties in Stormont's mandatory power-sharing coalition, acknowledged that more progress had been made on parades and the past than on flags.
Dr Haass, who is working alongside vice-chair Dr Meghan O'Sullivan, a US foreign affairs expert, said the onus on striking a deal rested firmly with the local politicians and stressed that no party would be able to achieve everything they wanted.
But he insisted the proposals on the table were much better than retaining the status quo and predicted they would get the backing of the majority of people in Northern Ireland. He said he did not believe he was asking anyone to sign up to anything that was unreasonable.
"We are getting close to what we call in America 'crunch time', we have got a few days left and the time has come I believe for parties and individuals to reflect hard - not simply on what it is they want but what it is they can live with," he said.
He and his team have an end-of-year deadline to report back.
The chair and vice-chair will present a third draft of proposals to the parties on Sunday ahead of a plenary meeting with all five parties on Monday morning.
Dr O'Sullivan said the goal was to reach agreement by Monday evening but if a deal was not reached then she and Dr Haass would make a judgement call on whether they would fly back to Northern Ireland on the 27th for further talks.
"We're now moving forward in what we hope is the culminating period of the process," she said.
A new authority for dealing with parades, which have been a major source of community division, and a unit for investigating the toxic legacy of a 30-year conflict which has left thousands dead and injured are among the Haass proposals which could become reality.
But a resolution of flags differences, which sparked pitched battles between loyalists and police earlier this year following restrictions on the flying of the Union flag from Belfast City Hall, appears further away.
"Both of us are committed to this process and to its success," Dr Haass said of himself and his vice chair.
"We have invested a lot of time and effort and we both believe there is great potential to offer the people of Northern Ireland a better way ahead but that potential will only become reality if this agreement is reached.
"We have made real progress today, particularly on the issues of parades and the past, we'll see where it is we come out on flags, but overall it would be a real loss for the people of Northern Ireland if the panel was unable to come to a successful conclusion."
"But we are working with the other parties to see if we can resolve those concerns and issues," said the Lagan Valley MP.
He did not rule out that a deal could be struck before Christmas.
"It looks like people share our view now that we are much better working through this and trying to get an agreement this side of Christmas, so I don't rule that out, but clearly we have some major hurdles to overcome before that becomes in any sense a possibility," he said.
Sinn Fein's Gerry Kelly said an agreement could be reached if the political will existed on all sides.
"It is our view that we can crack this before Christmas and we are glad that both Meghan O'Sullivan and Richard Haass and their team are in agreement with that, as well as the other parties," said the North Belfast Assembly member.
"We all want to do it before Christmas.
"There is still work to be done but we have made progress and we want to build on that progress."