Visitor numbers from Ireland to the United States fell by almost 27% in March compared to the same month last year, US figures show.
The drop of 26.9% was one of the steepest recorded across western Europe for the month, according to the figures from the US agency International Trade Administration published this week.
Overall, numbers from western Europe were down 17.2%.
Visitor numbers from Denmark fell by 33.9% last month compared to 2024.
Tensions between the United States and Denmark have soared after US President Donald Trump repeatedly said he wanted to take control of the resource-rich Greenland for security reasons.
Germany also recorded a drop of 28.2% last month compared to 2024.
Last month, the Department of Foreign Affairs in Ireland updated its travel advice for transgender people planning to visit the United States, noting authorities there want visa application forms to "reflect the traveller's biological sex at birth".
It said: "The US authorities have indicated that this should reflect, what they term, the traveller's biological sex at birth.
"Travellers whose sex on their passport differs from sex assigned at birth should contact the Embassy of the United States of America in Dublin for further details on specific entry requirements."
This week it was also announced that US immigration authorities would look at social media accounts and deny visas or residence permits to people who post content considered anti-Semitic by US President Donald Trump's administration.
Posts defined as anti-Semitic will include social media activity in support of militant groups classified by the United States as terrorists, including Hamas, Lebanon's Hezbollah and Yemen's Houthi insurgents.
