Attempts by former US diplomat Richard Haass to broker an agreement among Northern Ireland's political parties before Christmas failed early this morning.
Dr Haass chaired eight hours of discussions at a Belfast hotel but at 4.30am he told journalists he had not achieved consensus.
He is travelling home to the United States this morning.
On the basis of responses he receives to a fresh draft of proposals, he will decide whether to return to Northern Ireland at the weekend.
He also said that he and his colleague, Dr Meghan O'Sullivan, have work obligations after 1 January and ruled out involvement in further discussions beyond that date.
Asked if he was disappointed that the talks had not produced an agreement, he said he was not in the business of carrying out post mortems because the patient is still alive.
Naomi Long, one of the Alliance party delegation members, said the process is on life support.