Irish politicians and businesses have started preparing for the "biggest" challenge their economy has faced in over 50 years.
The U.K. has yet to negotiate with the EU the terms of its departure from the bloc, but officials from Northern Ireland and the Republic gathered in Dublin on Wednesday to discuss ways to offset the impact of Brexit.
'Common strategy'
Philip O'Sullivan, chief economist at Investec in Ireland, described Wednesday's meeting as a "good dialogue" to find a "common strategy."
Speaking at the event, Enda Kenny, the Irish prime minister, said that Brexit was the "most significant economic and social challenge of the last 50 years" and, thus, it was an issue with "potential to impact on everybody on the island, north and south," the BBC reported.
The Irish concerns range from the high level of trade with the U.K., to potential job losses and higher prices, as well as the future of the land border with the Northern Ireland and the peace process.
Busiest air route in Europe
Overall, the U.K. accounts for a sixth of Irish exports, Sullivan told CNBC over the phone. It is the biggest market for Irish food exports and the U.K. also plays a crucial role for the Irish tourism sector. The Dublin to London pair - flights between all airports in London and Dublin Airport - is the busiest air route in Europe and the second busiest international air route in the world.
Irish businesses share such concerns. "Brexit is going to be an issue for us as we look forward," Tony Smurfit, chief executive officer at Smurfit Kappa, told CNBC on Wednesday.
The head of the world's leader in paper-based packing, headquartered in Dublin, added: "I think right now we aren't seeing any particular demand issues, but when you look at our Irish business, when we export from Ireland into the U.K. that's going to affect us, unless we get price increases."