The Labour leader, Mr Ruairi Quinn, said he interprets yesterday's IRA statement as a cautious welcome for the Belfast Agreement, and that it should be seen in the context of the debate going on within Sinn Fein and the IRA.
On his first visit to Northern Ireland since becoming party leader, Mr Quinn said he could not agree with the view expressed by unionists that the statement represented a rejection of the document. The IRA had not denounced the agreement and had praised Sinn Fein's role in negotiations.
"I believe Sinn Fein supporters are engaged in what for them is a very difficult compromise. It is a compromise that was made by Fianna Fail many years ago. They have difficult steps to take. But there are difficult steps for everybody in this agreement," he said.
Mr Quinn was speaking at a press conference in the Belfast headquarters of the SDLP.
The issue of decommissioning could not be addressed now, but at a later stage. The most important thing was to get a large Yes vote in the referendum.
Mr Quinn said decommissioning was "an integral part of the agreement" but each stage of the process would have to be taken step-by-step.
The Irish people, North and South, and the British people in Northern Ireland had the opportunity show their support for peaceful means and the compromises contained in the agreement. "That will remove, utterly and totally, any vestige of legitimacy which the IRA may feel they have in respect of the use of violence and force."
Mr Quinn said the agreement was "a monumental achievement" and he saluted those who achieved it. It was a win-win agreement, based on compromise and accommodation.
"I'm here to support the SDLP and all the other parties who are anxious to see that what they negotiated will be vindicated by the people," he added.
Mr Sean Farren of the SDLP said that if the Irish people supported the agreement, the IRA would then have responsibilities on decommissioning. "Failure to follow up on that is a failure that they would have to live with the consequences of," he said.
Ms Brid Rodgers of the SDLP said a strong national consensus in favour of the Belfast Agreement, North and South, was necessary.
During his one-day visit, the Labour leader also held meetings with members of the Ulster Unionist Party, the Alliance Party, the Ulster Democratic Party and the Progressive Unionist Party.