Sinn Féin President Mr Gerry Adams and Ulster Unionist Party leader Mr David Trimble are to meet in the next 48 hours in an effort to break the deadlock over Tuesday's decommissioning by the IRA.
The meeting comes as Mr Trimble continues to insist that the deal he struck with Mr Adams has been put on hold rather than been abandoned.
He has suggested it could be restarted should the required transparency come.
Republicans have continued to defend Gen de Chastelain's decommissioning body, which Mr Trimble said had provided only "vague statements" about the IRA's decommissioning.
Mr Adams said yesterday the problems now encountered were more grave than the "glitch" suggested by Mr Blair at Hillsborough on Tuesday night.
He insisted republicans had lived up to their side of the deal.
Mr Adams suggested there were just days to sort out the problem because of forthcoming Assembly elections, a belief shared by a well-placed British source at Stormont.
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