A new joint task force tackling cross-border organised and paramilitary crime will have its first meeting next month.
It will include members of the Garda, Police Service of Northern Ireland, Revenue Commissioners and HM Revenue and Customs.
The Fresh Start deal agreed between the political parties and British and Irish governments in Belfast last month envisaged its establishment.
Details were announced at a meeting of Stormont, British and Irish ministers in Dublin.
First Minister Peter Robinson said: "Today marks an important milestone of the Fresh Start Agreement, with the Northern Ireland Executive moving forward with new justice structures."
Deputy First Minister Martin McGuinness said: "Criminality is a scourge on our communities, north and south, and we must be both united and relentless in our pursuit of these criminals."
The Fresh Start Agreement outlines plans that would bring together law enforcement agencies north and south of the border.
The announcement was also attended by Stormont justice minister David Ford and Dublin justice minister Frances Fitzgerald.