Gardaí will not be deployed in manning customs checkpoints along the Border in the event of a hard Brexit.
Justice Minister Charlie Flanagan made clear that he did not envisage a return to the "tougher, heavily armed" Garda patrolling of the Border that existed in previous decades.
A similar stance has been adopted on the northern side of the Border by PSNI Chief Constable Simon Byrne.
Mr Flanagan said gardaí would continue to be available in the region to combat terrorism and Border-related crime, including smuggling.
He said nobody was better placed than Garda Commissioner Drew Harris to be in a position to determine what was required in terms of Border policing.
He said an additional 150 gardaí had been sent to the region in the past two years and that policy would continue, while the provision of a third armed support unit, located in Cavan, was a big boost to the other units, based in Ballyshannon, Co Donegal, and Dundalk, Co Louth.
The minister emphasised that the greatest threat to the security of the State was posed by dissident republicans and every effort was being made to tackle those groups.
Mr Flanagan explained that the decision to recruit "up to" 700 new gardaí in 2020, rather than the previously announced 800, was influenced by his desire to allow the Garda Commissioner some flexibility in how he deployed the personnel under his control.
He said 800 gardaí had been recruited annually in 2017 and 2018, but it had been agreed that 600 gardaí would be taken in this year, allowing funding for Mr Harris to further increase the number of civilians in the force.
The current strength of An Garda Síochána is 14,200 and this is expected to rise to 14,400 by the end of the year.