All participants engaged in talks to save Northern Ireland's power-sharing political institutions must adopt a spirit of generosity, Stormont's Deputy First Minister has said.
Sinn Fein's Martin McGuinness said there was a "huge responsibility" resting on the five parties in the coalition Executive in Belfast and the British and Irish governments to push themselves to find a resolution.
The administration is teetering on the verge of collapse due to a crisis sparked by a murder said to be linked to the IRA.
However, its future viability had already been in doubt as a consequence of long-standing budgetary disputes, with the row over the non-implementation of the UK Government's welfare reforms the most vexed.
The fallout from the shooting of Kevin McGuigan and the other problems besetting power-sharing are on the agenda in the cross-party negotiations at Stormont House which have just began.
Before entering the discussions, Mr McGuinness said: "We are going into these discussions with a view to finding a resolution to the outstanding difficulties and to ensure there is a workable budget for the Executive.
"There is a huge responsibility on all parties, including ourselves, and also the two governments to be creative and deploy a spirit of generosity in the course of these discussions."
Ahead of the talks, Northern Ireland Secretary Theresa Villiers warned politicians not to waste the opportunity to build a better future.
The devolved Assembly has been thrown into disarray following the murder of Mr McGuigan last month.
The 53-year-old was shot dead in a suspected revenge attack for the murder of his one-time associate and IRA commander Gerard "Jock" Davison, 47, three months earlier.
A police assessment that individual members of the PIRA were involved alongside dissident republicans and criminal elements has rocked the political establishment and prompted unionists to remove all but one ministers from the Executive.