The Taoiseach says Donald Trump's comments are 'racist and dangerous' and the American people have an alternative to vote for.
Enda Kenny made the comments in the Dáil while answering questions on his recent trips to the United States.
He initially refused to be drawn on the matter, but eventually commented on the Republican party's presumptive nominee.
"Whoever the American electorate elect, the world will have to deal with their decision," the Taoiseach said.
"If Trump's comments are racist and dangerous - which they are - there is an alternative to vote for," he added.
Earlier this month, Enda Kenny travelled to Washington to mark events commemorating the 1916 Rising.
It was confirmed during the trip that US Vice-President Joe Biden is to travel to Ireland next month.
The Democrat, who has Irish roots, is expected to spend around four days here on a family trip.
