The meeting in London next week with the Democratic Unionist Party is "enormously significant" and "historic", the Taoiseach, Mr Ahern, has said.
The Taoiseach, along with the Minister for Foreign Affairs, Mr Cowen, will meet the DUP leader, the Rev Ian Paisley, and other leading party figures in the Irish Embassy next Thursday.
"This is a new phase. I think it is enormously important that this meeting will take place. It will be historic in its own terms," Mr Ahern said in Dublin yesterday.
He went on: "There was a lot of talk prior to Christmas that, perhaps, we would not get to this stage, so I always welcome breaking new ground. I think we have to engage.
"The real effort now must go into getting the Assembly back, the institutions working. That is my agenda. I don't have any hidden agenda."
The full review of the Belfast Agreement will not begin until February 3rd, though Mr Cowen insisted yesterday it would not involve the renegotiation of its fundamental elements.
He was speaking in Farmleigh after a British-Irish Intergovernmental Conference with the Northern Ireland Secretary of State, Mr Paul Murphy.
The governments, he said, would "listen very carefully" to the views of all parties. "We are hoping for constructive engagement by all parties."
Despite the optimistic declarations in public, there is deep pessimism in both Dublin and London about the prospects for the upcoming talks. "Things have never been gloomier," said one Irish source.
Meanwhile, Mr Cowen supported the Minister for Justice, Mr McDowell, who yesterday once again alleged that Sinn Féin was being funded by the IRA's involvement in organised crime.
Mr Cowen said: "The Minister for Justice speaks for the Government in relation to these matters, based on his own security briefings, and he has our full support in all of that.
"The Government's position is clear. We will continue to do whatever we can to deal with any criminality, under any guise, from whatever source."
However, Mr Cowen went on: "The Government finds itself in the position of having to maintain a peace process which is inclusive, working with all those people in the process who are committed to the transition to peaceful politics."
The joint communiqué released after the meeting pointedly noted that "continuing paramilitary crime, including racketeering, and threats of violence, were major public concerns.
"Both governments underlined their commitment to tackling such crime in all its forms."
Meanwhile, the International Monitoring Commission will be able to report on the level of security in place throughout Northern Ireland, along with commenting on paramilitary activity.
This could mean, for example, the commission could declare that military or police bases in particular areas were no longer justified by the level of terrorist threat, Irish sources suggested last night.
Questioned about the Oireachtas Justice Committee's inquiry into the Barron Report's findings on the Dublin/Monaghan bombings, the Northern Secretary, Mr Murphy, said: "We want to be as co-operative as best we can."