TAOISEACH Micheál Martin has warned that the north must not "spiral back to that dark place of sectarian murders and political discord".
Mr Martin was speaking on Saturday to mark the 23rd anniversary of the Good Friday Agreement.
His comments came after several nights violence in loyalist and nationalist areas.
"Perhaps its most visible success is that a whole generation of young people have grown up not knowing or experiencing the violence that accompanied the Troubles," he said.
"We owe it to the agreement generation and indeed future generations not to spiral back to that dark place of sectarian murders and political discord."
He said politicians have a role to play.
"There is now a particular onus on those of us who currently hold the responsibility of political leadership to step forward and play our part and ensure that this cannot happen," Mr Martin said.
"I am determined to work with the British Government, the executive and all political parties to protect the Good Friday Agreement, in all its parts."
Mr Martin said the 1998 peace deal marked a new beginning.
He called it a "a new era of peace and mutual respect - grounded in the principle of consent, peaceful politics, democratic institutions, reconciliation and co-operation".
"The Good Friday Agreement also introduced a new ethos of tolerance, equality and mutual respect to underpin the new institutional landscape," he said.
"The island of Ireland has truly become a completely different place in the last 23 years, because of the Good Friday Agreement. This has been a period of building trust, developing relationships, changing attitudes, and improving the lives of people on all parts of the island."
He added that it was vital to remember how much things have changed.
"It is important that we remind ourselves how far we have come and to continue to be profoundly grateful, to all of those at community level, who continue to work quietly every day and behind the scenes, for peace and reconciliation," he said.
Foreign Affairs Minister Simon Coveney said the anniversary served as a reminder of the responsibilities that come with the agreement.
"It continues to give us the foundations we needed for stronger relationships in Northern Ireland, north/south and on these islands.
"This has been a difficult and worrying week, but this anniversary comes as a reminder of the responsibilities we all have, as well as what politics, determination and dialogue can achieve.
"That is the spirit we need now."
