The unprecedented statement from the Prime Minister, Tony Blair, President Bill Clinton and the Irish premier, Bertie Ahern, came as violence erupted for a second successive night in Portadown and Lurgan following yesterday's funeral of the murdered human rights lawyer Rosemary Nelson.
With the first anniversary of the Good Friday Agreement rapidly approaching and cross-party talks in Washington on St Patrick's Day failing to resolve the stumbling block of arms decommissioning, the three leaders made a strong appeal for the courage needed to "finish the task" on peace.
The statement declared: "As we approach the first anniversary of the Good Friday Agreement, we can all take heart at how far we have come in a year.
"The agreement has provided the basis for the two traditions to work together, both in Northern Ireland and on the island as a whole, for the first time in 200 years. Democratically endorsed by an emphatic majority of people in both the North and South, it gives a unique opportunity for peace and reconciliation, in which all the signatories can take pride. It has rightly been acknowledged as an example to the rest of the world on how dialogue can bring an end to conflict."
The communique went on: "Large numbers of prisoners have been released on both sides of the border. That is an essential part of the agreement, although one that has caused undoubted pain to those who have lost loved ones during the years of conflict. The ceasefires remain solid."
The three leaders acknowledged the recent horrors that had afflicted all sides caught up in the turmoil: "Despite the progress, Omagh [bomb atrocity] demonstrated that the peace has not been a perfect peace.
"The cruel and senseless murder of Rosemary Nelson is a further reminder. But the response to Omagh showed that, despite the pain, there is deep determination in both the North and the South that peace is the only path. We call for an end to all the killings, and punishment beatings. Violence of the kind we have seen again this week must not be allowed to unsettle the peace process."
The statement takes some of the pressure off Gerry Adams, the Sinn Fein president, who yesterday reinforced his warning that he could not deliver on IRA decommissioning, but said there was a possibility of progress if he and Mr Trimble, first minister-designate in the Northern Ireland Assembly, could "jump together".
Mr Adams said Mr Trimble wanted "an event" to show that the IRA was prepared to disarm. "I couldn't deliver that," Mr Adams said, and Mr Trimble "knows it in his head and in his heart".
Pressure on Sinn Fein would not work: "Sinn Fein doesn't have to buy its ticket twice."Reuse content