An Ulster Unionist negotiator has said that a degree of trust is beginning to be built between his party and Sinn Fein in the Mitchell review. Mr Alan McFarland said contact between both parties has been "very beneficial".
However, he stressed substantial progress still had to be made before an agreement could be reached on decommissioning and the establishment of the executive.
"There is a degree of trust creeping in. Clearly, we have been at odds for 30 years and continue to be at odds politically, but they claim now to have turned away from a war path on to a peace path. We are clearly trying to establish if that is the case and that will take time," he said.
The UUP negotiator was speaking as his party and Sinn Fein held further discussions at Stormont yesterday. There were also talks involving the SDLP, Alliance, the fringe loyalists and the Women's Coalition. Meetings among all the parties will continue today in advance of Senator Mitchell's return to Belfast tomorrow.
Mr McFarland said the UUP was still trying to secure a commitment from the Provisional IRA to decommission. If that could be established, he said, the next stage in the negotiations would be to look at the process of disarmament under the supervision of Gen John de Chastelain, the chairman of the international decommissioning body.
Earlier, Mr Gerry Adams, who joined Mr Martin McGuinness for bilateral talks with Mr David Trimble and Sir Reg Empey, said the parties faced a crucial week.
"While there remains a small chance of breaking the impasse in the peace process, it can only happen if the political will is there amongst all the parties. Sinn Fein is committed to moving the process forward. This week will show if our commitment is matched by other parties."
Sinn Fein Assembly member Mr Gerry Kelly said he had hope about this week's talks but he was unable to "quantify or gauge it".
Progressive Unionist Assembly member Mr David Ervine said he believed a deal could be reached. However, he advised against overoptimism. "It really would be foolish to build hopes up and dash them. It can be done but we have to wait and see. There is still a fair bit of work to do."
Mr Peter Mandelson yesterday said nobody in the North would have a "decent future" if the Belfast Agreement wasn't implemented. "Everyone stands to gain - every part of every community in Northern Ireland. We all need it desperately," he said.
"I believe the politicians want to reach a deal to implement the agreement. I know that if they listen to the public in Northern Ireland in both communities, they will want to do a deal."
The Northern Secretary was speaking during a visit to RUC headquarters, where he discussed the Patten report on policing with the Chief Constable, Sir Ronnie Flanagan.
The Conservative Northern Ireland spokesman, Mr Andrew Mackay, held talks with the SDLP deputy leader, Mr Seamus Mallon, at Stormont yesterday. He urged the paramilitaries to "prove they genuinely have democratic credentials".
A group of business and trade union leaders pledged its support for the Mitchell review and the implementation of the Belfast Agreement. A statement said: "We urge the parties to go with the heave of history and reach forward to grasp the enormous prize within reach."
It was signed by Ulster Bank chairman, Sir George Quigley; the chairman of the North's Confederation of British Industry, Mr Chris Gibson, and the organisation's director, Mr Nigel Smyth; the chairman of the Institute of Directors, Ms Ann Shaw, and its director, Ms Linda Brown.
The pro-agreement group, People Moving On, has said it is holding another demonstration at Stormont tomorrow.
A group of Belfast-based artists, including Ms Rita Duffy, Mr Gary Shaw and Ms Amanda Montgomery, said the North's parties should set up the executive.