The Government remains "resolute in its determination" to bring those responsible for the Omagh bombing to justice, the Taoiseach said today.
Mr Ahern was speaking after meeting relatives of victims in Dublin this morning. The meeting with the Omagh Victims' Group was also attended by the Attorney Genera, Mr Rory Brady SC.
The group travelled to Dublin to press the Government to support their case for the establishment of a public inquiry by the British government. The "Real IRA" bombing in Omagh in August 1998 claimed the lives of 29 people, including a woman pregnant with twins.
Mr Ahern said the Garda investigation into the bombing was "active and ongoing".
He added: "We know that dissident groups continue to plan further attacks. They must be stopped. They cannot be allowed to wreck more innocent lives."
Mr Ahern has met a number of families bereaved by the Omagh bombing before but members of the Omagh Victims' Group have failed to meet him in the past, claiming tight time restraints were placed on proposed talks.
He travelled to Omagh last month to lay a wreath in honour of those killed. However, the victims' group travelled to Dublin on the same day to meet the Fine Gael leader, Mr Enda Kenny.
Mr Michael Gallagher, whose son Aidan was killed in the bombing, said the relatives accepted today's invitation in the hope that it could mark a fresh start in the group's relationship with the Government.
Speaking before the meeting he said: "This is the first meeting in any context we've had with Bertie Ahern and I have never shaken his hand before".
"But we acknowledge this as a positive move and we accepted the invitation in the spirit it was extended.
"The outcome of this meeting is the important thing. We want to leave any embarrassment or difficulty behind us and if we can get the Government on our side to push the British government to hold a public inquiry into what happened in Omagh, then it will be a major success.
"The Irish Government called on the British government to establish a public inquiry into Bloody Sunday and it was set up. We merely want the same treatment," he added.
The Minister for Justice, Mr McDowell, has offered to provide the group with a further briefing on March 23rd. Following today's meeting the Omagh group met with the Garda Commissioner in Government Buildings.