Brexit could result in 300,000 fewer UK holidaymakers visiting Ireland by the end of 2017, compared with the previous 12 months, it has been warned.
Fáilte Ireland said this could have resulted in €88m in lost revenue and 1,900 lost tourism jobs had there not been a strong performance in other markets, particularly the US.
There were 3.6 million UK visitors in 2016, but Failte Ireland is predicting 300,000 fewer by the end of this year.
The authority is to target cross-border holidaymakers in a bid to off-set the anticipated impact of Brexit on the industry.
Fáilte Ireland said it intends to significantly increase spending in Northern Ireland in early 2018 in an attempt to encourage travel south of the border, particularly key border counties, in the off-season.
Research is also being conducted on the development of luxury breaks, outdoor adventure activities and the retention of golf tourism, which is worth about €100m annually to the economy from the UK and North American markets.
Fáilte Ireland CEO Paul Kelly said the "volatility generated by Brexit during the last year would have led to significant revenue and job losses had other traditional markets, particularly the US, not performed so well."
He warned: "We cannot always assume that other markets will continue to compensate in this fashion - particularly as we now face a challenge in those markets from a British tourism product made much more competitive by the lower sterling value."
Mr Kelly said the ongoing Brexit volatility underlines "the extent to which tourism can be at the mercy of external factors beyond our control."
He added: "However, we can meet our current challenges by working on those things which remain within our control - our visitor experiences, competitiveness, capacity and skills."
He was speaking at the launch of Fáilte Ireland's Get Brexit Ready support programme designed to help businesses at risk or already struggling with the loss of trade created by Brexit.
The website is a one-stop shop for all the relevant information and insights that businesses will need - from development supports and training programmes to insights and market intelligence.