Richard Haass talks continuing into night
Talks between Northern Ireland's five main parties and former US diplomat Dr Richard Haass are continuing into the night.
A deadline for agreement on three contentious issues - the past, parades and flags - had been set for Monday evening, but talks have not finished.
The parties are now set to negotiate on a seventh draft of the proposals.
The next round table session was expected to begin at 01:30 GMT and it is not clear how long it will continue.
Among the contentious issues in the sixth draft were a plan for a trauma centre for Troubles victims and a code of conduct for parading, BBC NI political reporter Stephen Walker said.
Another issue believed to be causing concern for some parties was how people could be compelled to give evidence into historical enquiries.
Arriving at the talks on Monday, Sinn Féin's Gerry Kelly said he was "fairly confident" a deal could be reached.
"We are hopeful we can do a deal today," he said. "These issues will not go away so now is the time to deal with them."
On Sunday, Ulster Unionist leader Mike Nesbitt had said the talks were "80 to 90% over the line".
Delegations from the parties - except the DUP - met Dr Haass separately on Sunday.
The DUP did not take part as it does not negotiate on Sundays.
Sinn Féin's Martin McGuinness said Dr Haass and his co-chair, Prof Meghan O'Sullivan, must not be allowed to return to the United States without securing a deal.
"It would be a humiliation if Richard Haass and Meghan O'Sullivan left here against the backdrop of no agreement," he said.
A spokeswoman for the US National Security Council said the talks were at a critical juncture and the goal remained to achieve agreement before the end of the year.
"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," she said.
The Secretary of State for Northern Ireland, Theresa Villiers, said: "I hope all sides will be able to show flexibility to make an agreement possible on these divisive issues.
"From my many conversations on this over recent days, I am encouraged about the prospects for agreement, although some key issues are yet to be resolved, particularly on the past."
Commenting ahead of the final stages of the talks on Monday evening, Ivan Lewis, shadow Northern Ireland secretary said: "Dealing with the causes of ongoing tensions and the unresolved traumas of the past are the key to building a better shared future for the people of Northern Ireland.
"Based on my discussions with key participants in the talks over the last few days, it is clear a substantive agreement on parades and dealing with the past is within reach.
"I hope Northern Ireland's political leaders will demonstrate the courage to make challenging but necessary compromises and the UK and Irish governments are doing everything in their power to secure a positive outcome."
Dr Haass and Prof O'Sullivan were brought to Northern Ireland in July by the first and deputy first ministers.
They returned to the US for Christmas after talks broke up without agreement in the early hours of Christmas Eve.