Northern Ireland citizens face fines of €100 if they cross the border on a non-essential trip.
New measures come into force at 7am Monday to limit people crossing the border or being in the State without a reasonable excuse.
Anyone breaching the regulations is liable receive a fine of €100. The fines will also apply to each passenger in a vehicle.
Gardaí said they will continue to use the 4Es – engage, explain, encourage and, as a last resort, enforce.
An Garda Síochána is also continuing to conduct checkpoints on access roads to airports and ports, as well as in departure areas, to check on whether people travelling to these locations are undertaking an essential journey. Travelling to an airport or port to take a holiday abroad is not an essential journey.
Since 29 January 2021, Gardaí have issued approximately 375 fines at Dublin Airport to people for leaving the country for non-essential travel.
To date, An Garda Síochána has issued approximately 4,600 fines for breaches of COVID-19 regulations. Of these, 3,523 have related to non-essential travel.