Every area of economic and social life on the island of Ireland has the potential for enhanced cross-Border co-operation, according to the Taoiseach, Mr Ahern, who was accompanied to yesterday's inaugural meeting of the North-South Ministerial Council by his entire cabinet.
Mr Ahern described yesterday's meeting in Armagh, which was also attended by 10 ministers of the Northern Executive, as "a day quite unlike any other".
He said the Ministerial Council's work would be cemented by guiding principles which would ensure that all projects would be mutually beneficial, undertaken efficiently and only executed following agreement from all participants.
Speaking after the 90-minute meeting, which agreed the locations of offices for the six cross-Border implementation bodies and appointed members to four boards, the Taoiseach added: "Of course over the months ahead we will have difficulties but we'll work those out as we have right through."
The North's First Minister, Mr David Trimble, said the Ulster Unionist Party was happy to partake in cross-Border co-operation because it now operated on a "very sound basis" of mutual recognition, agreement, with accountability to the council, the Dail and the Assembly.
The Tanaiste, Ms Harney, said yesterday's events represented an end to the bloody, divisive and bitter past on the island and the start of a "new positive chapter".
In an era of the global economy, she stressed her belief that a political structure was necessary to enable politicians on both sides of the island to deal with areas of mutual interest. The North's Deputy First Minister, Mr Seamus Mallon, said he felt that Northern Ireland was leaving the past behind and taking a step into the future.
Responding to questions, Mr Ahern warned that those who attempted to oppose the peace process by force would be subjected to the full weight of the law.
He also expressed confidence that arms decommissioning would take place. "The message is that we want to see all aspects of this agreement implemented and of course the "D" word [decommissioning] is one of those things that has to be implemented."
Mr Trimble rejected the suggestion that the planned February reconvening of the Ulster Unionist Council to assess progress on decommissioning amounted to a deadline. "I have not set a deadline. It's in the hands of Gen de Chastelain."
The UUP leader said the two DUP ministers - Mr Nigel Dodds, Minister of Social Development, and Mr Peter Robinson, Minister of regional development - were as involved in the new bodies as the other ministers because they had taken their seats in the Executive.
He also expressed his appreciation to the Garda Siochana and the RUC for their work in clamping down on dissident paramilitaries.