Round-table talks between the two governments and the North's pro-agreement parties are likely to take place next Tuesday, according to a senior source close to the negotiations.
The talks had been expected to take place today with the weekend regarded as a deadline. However, a meeting between the Taoiseach and the British Prime Minister, Mr Tony Blair, on Wednesday in London appeared to end on a down-beat note, with Mr Ahern saying he did not envisage an imminent breakthrough.
Yesterday the source said both governments were being "realistic rather than pessimistic" and were "working towards" a breakthrough rather than being on the verge of it. The Taoiseach's trip to Japan next Thursday would be a natural deadline to the discussions, he added.
A Sinn Fein spokesman said his party had not given up on the process but did not detect the political will to resolve the impasse. A "considerable gap" remained to be closed, he said.
A plenary meeting of the North-South Ministerial Council in Armagh today has been called off. An Ulster Unionist spokesman confirmed the party leader and First Minister, Mr David Trimble, and his three ministerial colleagues had refused to attend.
The Sinn Fein president, Mr Gerry Adams, blamed both the UUP leader and the British government for the cancellation of the meeting. "Mr Trimble's ability to behave illegally and with impunity is very much the responsibility of the British government which has failed to use its legislative powers and make Mr Trimble pay a price for his subversion of the Good Friday agreement," he added.
Mr Adams also called on Mr Blair to "state categorically" that he would not suspend the North's devolved institutions.
The Alliance Party deputy leader, Mr Seamus Close, criticised the two governments for postponing the North-South Ministerial Council meeting, accusing them of "political drift" and "lack of direction".
There is uncertainty whether the outbreak of foot-and-mouth disease will affect the dates for the British general election as well as local council elections, scheduled for May. Nationalists complained previously that the British government was already in "election mode" and was not focusing its full attention on the ongoing talks.