The number of UK visitors here fell by almost 6.5%
New figures show the number of tourists visiting Ireland was up 4.2% for January to June this year.
Tourism Ireland say this was the best ever month of June for Irish tourism, with almost one million arrivals.
The Central Statistics Office (CSO) numbers show:
However visitors from Great Britain dropped for the same period by 6.4% to 1.745 million visits.
Niall Gibbons, CEO of Tourism Ireland, said: "It is encouraging that this was the best ever month of June for Irish tourism, with almost one million arrivals.
"Particularly welcome in today’s CSO figures is the continued strong performance from North America, with an increase of 21.6%.
"Tourism Ireland has prioritised North America for 2017, as a market which offers a strong return on investment, in terms of holiday visitors and expenditure.
"A number of factors are working in our favour, including more airline seats than ever before, from more gateways across the US and Canada.
"Visitor numbers from Australia and developing markets for the first half of 2017 are also really strong, up 20.6%".
Mr Gibbons added that "important markets" like Germany, France and Spain are continuing to perform well.
"As anticipated, the currency challenge for Irish tourism is very real and the drop in British visitor numbers for the January to June period reflects that.
"The decline in the value of sterling has made holidays and short breaks here more expensive for British visitors; and economic uncertainty is undoubtedly making British travellers more cautious about their discretionary spending."
Tourism Minister Shane Ross welcomed the data: "Following the strong growth in recent years, it was always going to be a challenge to grow the numbers further this year.
"For that reason, I am very encouraged by the results for the first half of the year, particularly the figures for North America.
"Nonetheless, everyone involved in Irish tourism knows that we are not immune to the economic uncertainty in Britain, our largest overseas source market in terms of visitor numbers.
"I will continue to remain vigilant on this front but, overall, the picture remains positive."
In 2016, Ireland welcomed approximately 10.3 million overseas visitors, delivering revenue of about €5.3bn.