The deepening crisis in the peace process will be the focus of talks between the Taoiseach, Mr Ahern, and the British Prime Minister, Mr Tony Blair, when they spend tomorrow in London and at Chequers.
Speaking to journalists in Dublin yesterday, Mr Ahern said the document produced after 10 hours of discussions in Downing Street last Friday still provided the basis for agreement.
Progress would have to be made within the parameters of the Belfast Agreement and there was a "determination" this should remain the case.
"Prime Minister Blair and myself are determined to keep moving and keep trying right up to the June 30th deadline . . . We have to be careful not to be too pessimistic," Mr Ahern said. The Ulster Unionist Party had misunderstood the agreement that he believed had been reached on Friday, he said. The executive would be established but work would continue, in parallel, to meet the decommissioning requirements by April 2000.
On the Drumcree standoff, Mr Ahern said agreement could only be reached through direct dialogue.
"We are heading to Drumcree 5 and it is only local dialogue and engagement that will avoid what could potentially be a very difficult situation," he said.