US diplomat Dr Richard Haass has vowed to ‘leave no stone unturned’ in an effort to resolve the flag crisis in Northern Ireland before he flies home for Christmas.

The specially appointed US envoy has vowed to resolve outstanding peace process issues before Christmas Eve.

Haass has described this weekend as crucial in negotiations between both sides of the political divide aimed at resolving the flag, parades and legacy of the past issues.

He is currently chairing talks between the five parties represented in the Northern Ireland assembly.

Working alongside vice-chair Dr Meghan O’Sullivan, a US foreign affairs expert, Haass has admitted that the flag issue, which has led to riots in Belfast, is proving the most difficult to resolve.

He told reporters that the onus on striking a deal rests firmly with the local politicians and stressed that no party would be able to achieve everything they wanted.

The Irish Independent reports that Haass insisted that the proposals on the table are ‘better than retaining the status quo’.

The former US envoy to Northern Ireland predicted the proposals would get the backing of the majority of the people and does not believe he is asking anyone to sign up to anything that was unreasonable.

After further talks on Friday, Haass said: “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.

“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.”

Haass and O’Sullivan will present a third draft of proposals to the parties on Sunday ahead of a plenary meeting with all five parties on Monday morning.

O’Sullivan told the paper: “The goal is to reach agreement by Monday evening but if a deal is not reached then we will make a judgement call on whether we 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.”

Proposals include a new authority for dealing with parades and a unit for investigating the toxic legacy of a 30-year conflict which has left thousands dead and injured.

The resolution of the flag issue appears more distant.

DUP negotiator Jeffrey Donaldson said: “My party still has very serious concerns about key elements across all three areas.

“But we are working with the other parties to see if we can resolve those concerns and issues.

“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.”

Sinn Fein’s Gerry Kelly told reporters that an agreement could be reached if the political will existed on all sides.

He said: “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.

“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.”