The Taoiseach held telephone talks with Ulster Unionist leader Mr David Trimble late last night in a bid to persuade him to re-enter the review of the Belfast Agreement.
Sources said Mr Ahern tried to convince the Ulster Unionist leader there was nothing to be gained by remaining outside this phase of the review process.
Earlier, Mr Trimble had called on Northern Ireland's political parties to pull out of talks on restoring devolution and to isolate Sinn Féin.
Speaking after talks with the British Prime Minister Tony Blair at Downing Street, Mr Trimble urged the Democratic Unionist Party, the nationalist SDLP and the Alliance Party to follow his lead and abandon talks on the review of the Belfast Agreement.
Mr Trimble walked out of the review after the British government refused to throw Sinn Féin out following the attempted abduction of a dissident republican - which the IRA denies any involvement in.
Speaking after hour-long talks with Mr Blair and Northern Ireland Secretary Paul Murphy, Mr Trimble said the incident demonstrated the underlying problem of continuing paramilitary activity.
"There is no point continuing with the review when it is clear that the underlying problem is not resolved and indeed that the republicans have not come to the point of making the crucial decision and change towards peace and democracy," he said.