The government expects agreement within two weeks on "at least six" of the North-South implementation bodies, after a "very good" meeting yesterday between the Taoiseach and the First Minister, Mr David Trimble.
The two men met for an hour at Government Buildings and afterwards agreed that considerable progress had been made.
Mr Ahern said matters had "moved on significantly and substantially", while Mr Trimble agreed it had been a "very positive" meeting.
In separate speaking engagements in the Republic during the day, Mr Trimble stressed the need for decommissioning, and accused Sinn Fein of effectively breaching the Mitchell Principles during the recent incident in which Belfast's Donegal Celtic football club withdrew from a match against the RUC after alleged threats to players.
However, a Government spokesman said that Mr Trimble had appeared convinced of the need to "push forward" with the North-South bodies now. The spokesman added that "at least six" areas would be agreed in the next two weeks, clearing the way for legislation which would have them up and running by the February deadline.
Mr Trimble told the Irish Association last night that increased North-South co-operation was possible, provided it "is no longer advanced as a strategy for creeping unification".
At the annual conference of the association, in Glen of the Downs, Co Wicklow, he said that in the wake of the Belfast Agreement "there is no longer any need to engage in such tactical manoeuvres, and a growth in co-operation is consequently possible".
But he warned that it would be misleading of him not to caution against "unrealisable expectations" for the North-South implementation bodies. These had a role "in certain small, discrete areas", of which animal health and management of waterways were two examples.
The potential for co-operation between Government Departments and between business, voluntary and community bodies was "considerable", he added. But he cautioned against "those who seek to rewrite history, who see history rolling inexorably in one direction.
"That is a lesson which must be learned if sterility is not again to inform North-South relations. Is it not better to say `This area has proven potential, let us see how we can build upon it' rather than, `This was on the agenda in 1965 and 1973, and the situation now demands more'? Perhaps there were sound economic reasons why those schemes were not successful."
Mr Trimble also told the conference that there could be no progress towards an executive role for Sinn Fein while they maintained a "no, nothing, never policy" on decommissioning.
He said the Donegal Celtic episode was an example of Sinn Fein's continuing ambivalence towards the democratic process.
"There was a secret ballot. It did not go Sinn Fein's way. Then the hard men were deployed."
This could not be the way of the future, he added. "So long as no start has been made towards the total decommissioning of all the terrorist arsenals, a constant implied threat remains - a threat made explicit when Martin McGuinness wrote recently in The Irish Times that the fact that the guns were not now in use was of immense significance. `Not now' were his very words, words laden with menace."
Earlier yesterday, addressing the Association of European Journalists in Dublin, Mr Trimble said that the Donegal Celtic incident amounted to a breach both of the Mitchell Principles and the ceasefire. He admitted there was no absolute proof of Sinn Fein's involvement: "But this was in Gerry Adams's backyard - can there be any doubt?"
In his speech last night, however, Mr Trimble insisted he was not pursuing "an exclusionist strategy" concerning Sinn Fein. "As I said at the first meeting of the Assembly - and I was looking directly at them when I said it - we have never said that people with a past do not have a future."
Ulster Unionists were open to "new relationships, changed relationships", he added, "so long as it is done with integrity".
Asked at the European Journalists meeting if he was worried by the attendance on Thursday night of Dr Ian Paisley and Mr Robert McCartney at a "Union First" rally in Belfast organised by UUP members, Mr Trimble suggested the rally was effectively organised by Mr McCartney and Dr Paisley.
"It's the old story of who's who," he said. "Who's going to end up on the back of the tiger and who'll end up inside?"
