The situation in Northern Ireland is "very dangerous at the moment" following the recent murders, the Taoiseach has said.
Mr Ahern condemned the "quite brutal and primitive campaign of sectarian murders". They must ensure that those determined to destroy the talks process - and that was what they were trying to do recently - would not allowed to succeed.
He told political correspondents that neither the Governments nor any of the parties at the talks should allow themselves to be intimidated, deflected or drawn in "by this blatant attempt to veto political progress".
"We either give up or we stand up. As far as I am concerned, we are not going to allow the situation to plunge back into conflict," Mr Ahern stated. "I couldn't say to you that there are not evil people out there who are prepared to do an awful lot more to try to derail us. We can't allow that to happen," he continued.
Expressing his determination to move on with the talks process, Mr Ahern said the parties had agreed yesterday to move quickly from the "general principles to the details of an overall settlement".
The two governments would present a joint paper on Strand Two - the North-South dimension - in London next week.
Asked if this paper would flesh out a North-South body with executive functions, Mr Ahern responded that the Heads of Agreement Document: "As far as I am concerned and those that negotiated it with me, is executive bodies. It was then, it still is and it will be next week."
The basis for their position on Strand Two was set out in the Framework Document. He thought that in time it would be helpful if they dealt with realities of substances, rather than perceptions.
Returning to the "difficult" situation at present, Mr Ahern said that the growth of sectarian killings by fringe paramilitary organisations with no mandate from anybody which were repudiated by most people of all denominations on these islands, was a "very worrying development".
The Tanaiste, Ms Harney, said that the events of the last 72 hours should not deflect them from the search for a lasting political settlement in Northern Ireland. The men of violence should never be allowed to dictate the pace and shape of events on this island.
Meanwhile, the Fine Gael leader, Mr John Bruton, will hold a series of meetings with political leaders in Northern Ireland when he visits Castle Buildings in Belfast today. He will also meet the Secretary of State, Dr Mo Mowlam.
He will be accompanied by his deputy spokesman, Mr Charles Flanagan.
