No deal has been reached in the U.S. brokered talks to settle outstanding issues in the Northern Irish peace process.

The issues at stake were flags, parades and how to handle the legacy of The Troubles.

However, former US diplomat Dr Richard Haass, who chaired the talks, said that while a final agreement was "not there" there had been "significant progress."

He called it a "basis" for change.

Sinn Fein agreed the deal but the largest Unionist party, the DUP, said more work was needed.

"All the parties support significant parts of the agreement. At the same time, all have some concerns," Dr Haass said.

"We very much hope that the parties reflect on this, discuss it with their leadership and then come back with a strong endorsement. Over the next week we will know a lot more."

Haas said agreement had been reached on handling the past but that flags and symbols were the "toughest area of negotiations."

"It would have been nice to have come out here tonight and say we have got all five parties completely signed on to the text," he said.

"We are not there but I believe there is a real prospect that we will get several of the parties to sign on the text in full."

Sinn Fein's Gerry Adams said there was a "basis for a deal in the proposals put forward though it was "not perfect."

"I'm sure there will be a lot of disappointment out there as people come to terms with the fact that there doesn't appear at this point to be an agreement," he said.

However, the DUP's Jeffrey Donaldson said, "some of the language and detail is not what we would have chosen and in some cases we strongly disapprove of the language."

"We entered into this process to get the right deal for the people of Northern Ireland, but not any deal," he added.

"We do not have an agreement this evening but we are committed to continuing this work beyond now in dialogue with others to try and resolve the outstanding issues that need to be addressed," he said.

"We owe that to the people of Northern Ireland, especially to the innocent victims of terrorism who have suffered so much over the decades."

The chair and vice-chair of the negotiations affirmed that, no matter the outcome, they would continue to work towards lasting peace in Northern Ireland. Prior to the final round of talks, Dr. Haass told the Belfast Telegraph that he and Harvard professor and former Bush foreign policy strategist Dr. Meghan O’Sullivan have been in touch with "officials at the highest levels of the British, Irish and American governments," and that going forward they would act as advocates for the three governments as further steps are implemented.

Haass also stated that should the parties fail to agree on a proposal, early in the new year he and Dr. O’Sullivan would publicly release their own report addressing, “all the issues that have been central to this negotiation, and we will give our thoughts in such a context – not in a way that reflects the consensus of the parties but rather that reflects a joint consensus between us.

“We are prepared to speak truth to power if it comes to that, but we would much prefer to have power itself embrace a road map for its own future," he added.

The multilateral talks were first announced in July , after a number of outbursts of violence stemning from hot-button issues such as parade routes and the decision to only fly the Union Jack above Belfast’s City Hall on designated days drew international attention to the lingering obstacles along Northern Ireland’s road to peace.

Dr. Haass, director of the New York-based Council on Foreign Relations and the U.S. envoy to Northern Ireland from 2001 to 2003, was selected by First Minister Peter Robinson, deputy First Minister Martin McGuinness, and the leaders of the five main political parties as the chair of the negotiations, and Dr. O’Sullivan, a Harvard professor of international relations and the former deputy national security advisor on Iraq and Afghanistan to President Bush, was named as Haass’s vice-chair.

The talks officially commenced in September, with flags, parades and the question of how to address Northern Ireland’s past in contexts both commemorative and legislative as the three key issues to be considered in a unilateral proposal.

While a more holistic, compromise-based approach to peace has often been necessary in Northern Ireland, where long-held traditions and associations can butt heads with more straightforward progress, Haass and O’Sullivan have taken a firm and at times controversial stance.

After breaking for Christmas, they returned to Northern Ireland over the weekend, sending a sixth draft of the proposal to party leaders on Sunday night. A seventh draft was issued on Monday night, at 11pm GMT.

Calls for decisive progress came from within Northern Ireland and around the world. As reported by the BBC Secretary of State for Northern Ireland Theresa Villiers expressed hope that “all sides will be able to show flexibility to make an agreement possible on these divisive issues.”

Sinn Fein's lead negotiator Gerry Kelly echoed her optimism, stating “"We are hopeful we can do a deal today . . . These issues will not go away so now is the time to deal with them," while UUP leader Mike Nesbitt issued an encouraging estimate that  “80, maybe even 90%” of the proposal was “over the line.”

In a statement, the White House urged all involved to work towards a conclusion. “We call upon the leadership of the five parties to make the compromises necessary to conclude an agreement now, one that would help heal the divisions that continue to stand between the people of Northern Ireland and the future they deserve,” said spokeswoman Caitlin Hayden.

Haass had voiced his hopes for the final day of meetings via Twitter:  “have long said the only day of a negotiation that counts is the last day. [sic] today is the last day here in Belfast. Hope NI leaders seize it.”