The Taoiseach has indicated that the republican movement must now respond to Mr David Trimble's declaration that he would consider a restoration of the North's political institutions without "arms up front".
Mr Ahern yesterday welcomed Mr Trimble's offer to consider such a formula as a "very helpful statement". Effectively calling for a positive response from the republican movement, he said there were now aspects of what Mr Trimble said, including the decommissioning issue, that "others must declare on".
Mr Trimble made his offer of renewed flexibility at a press conference in Washington yesterday. "We are prepared to be involved in a fresh sequence which probably will not involve arms up front," he said.
He declined to give details of what formula, amounting to less than "arms up front", his party would be prepared to become involved in, but said: "We need to know it's going to work."
He said that in order to be able to become involved in a new sequence, "I've got to be able to persuade the party to do it."
The anti-agreement Ulster Unionist Party MP, Mr Jeffrey Donaldson, has said he would be "absolutely astonished" if his party embraced a policy which allowed Sinn Fein back into government without decommissioning.
The UUP security spokesman, Mr Ken Maginnis, insisted that his party was committed to the policy that "illegal organisations and guns are incompatible with democratic government".
Mr Trimble's declaration of flexibility, coupled with the holding out of the prospect this week of further demilitarisation moves by the British, has put further pressure on the republican movement to indicate what, short of prior decommissioning, it is prepared to do to ensure the restoration of the institutions.
There was hope in Government circles last night that the republican movement would now engage in detailed discussions about a formula.
The Taoiseach discussed the state of play in the peace process with Mr Clinton for 30 minutes yesterday afternoon, following which the US President held separate talks with Mr Trimble, Mr John Hume and Mr Seamus Mallon of the SDLP and the Sinn Fein president, Mr Gerry Adams.
President Clinton accepted the traditional St Patrick's Day bowl of shamrock from the Taoiseach yesterday afternoon. At the presentation ceremony in the White House President Clinton promised continued US support for the peace process.
The presentation ceremony was also attended by the Minister for Foreign Affairs, Mr Cowen, the Minister of State for Foreign Affairs, Ms Liz O'Donnell, and leading Irish-American political figures.
The Taoiseach and the British Prime Minister will discuss the latest developments on Monday by telephone. They will meet later next week, probably on Thursday, on the fringes of the Lisbon EU Summit to attempt to devise a joint strategy to have the institutions restored.
However, Government sources also acknowledge that the outcome of the Ulster Unionist Council meeting next Saturday is a key to progress. Government sources are keen to know whether Mr Trimble has support from within his party for again entering the all-party executive without decommissioning taking place.
Reliable sources say republicans have not up to now engaged in detailed talks of what they would be willing to do to have the institutions restored.
The reason given, according to the sources, is that they do not believe the UUP are willing to discuss formulas the republican movement believes to be attainable. Mr Trimble's statement of yesterday is therefore seen as a significant move.