The Taoiseach and the British Prime Minister will have a mid-air meeting on the North on Thursday when they share a flight to Croatia.
Both Mr Ahern and Mr Blair are travelling to the Croatian capital, Zagreb, for an EU-Balkans summit. When officials discovered their itineraries did not allow time for a meeting on the ground, it was decided they would share a flight, with the British offering a lift to Mr Ahern.
The Attorney General, Mr Michael McDowell, will be travelling with Mr Ahern.
Mr Ahern and Mr Blair are due to discuss the Patten Report on policing in Northern Ireland, decommissioning, and demilitarisation. According to a Government spokesman, the purpose of the meeting would be to "solve the impasse which is there at the moment".
Irish and British officials met in Dublin at the end of last week and the Blair-Ahern meeting will continue where those discussions left off, said the Government spokesman.