Armed gardaí will be on patrol during the Royal Visit of Prince Harry and Meghan Markle in Dublin this week.
According to The Herald, authorities fear a dissident republican attack on the couple.
While gardaí say there is no known plot, a major security operation will be in place when they arrive tomorrow for their two-day state visit.
The Duke and Duchess of Sussex's visit to Ireland tomorrow is expected to boost Irish tourism.
The couple arrive tomorrow for a two day trip which will highlighting a number of popular visitor attractions including Croke Park, Trinity College and the Book of Kells, the Famine Memorial and EPIC, the Irish Emigration Museum.
"We are delighted that Megan and Harry have chosen Ireland for their first trip abroad as the Duke and Duchess of Sussex and that they are visiting some of Dublin’s brilliant visitor attractions," said Paul Kelly, CEO of Fáilte Ireland.
"In particular, the coverage from this royal visit will provide a boost to the UK market which has been a challenge in light of Brexit.
"As the national development authority, Fáilte Ireland will continue to work with tourism businesses throughout the country to ensure that they can fully capitalise on the afterglow of the visit."
In 2011, the visits of Queen Elizabeth II and President Obama generated at least €298 million worth of publicity through some 37,795 separate print and broadcast pieces, resulting in an uplift in visitor numbers that year.
"It is an honour to be welcoming the Duke and Duchess of Sussex to EPIC," said Neville Isdell, the museum's founder and chairman.