Taoiseach Enda Kenny says he has nothing to apologise for, as he meets with US President Donald Trump.
The two men will meet for nearly an hour in the Oval Office, in Mr Trump's first meeting with a pro-EU leader.
But planning has been overshadowed by a gaffe, which saw journalists given a speech in which Mr Kenny planned to indicate his resignation.
This line was taken out of a revised version of the speech.
Asked why the line was removed, Mr Kenny told journalists: "The speech that you got is not the speech I'm delivering tonight, that's why".
Last year the Taoiseach said President Trump's language was "racist and dangerous" - but says there is no need for an apology.
Mr Kenny said: "My comment was in respect of his language...language and words can be used by people in many regards.
"My comment was when he was running as a candidate in respect of the election to be held.
"My meaning was not in any way personal to him."
Pushed on the issue by Newstalk's Chris Donoghue, Mr Kenny said: "I'm not into English classes - I'm telling you that the language that was used on that occasion was, in my view, not language that I would use - but that was not related to his personality".
Mr Kenny added: "I haven't come to America to answer to Nigel Farage - I am the leader of the Irish Government, and very proud and privileged to be so.
"I'm responding to an invitation sent by the President of the United States.
"I'm very happy to go to the White House, and to continue the traditional connection between Ireland and the United States".
Here's the press conference with Enda Kenny on a timeline for stepping down and his comments about #DonaldTrump pic.twitter.com/aZgrCAO2QC
— Newstalk Drive (@NewstalkDrive) March 15, 2017
As Mr Kenny prepares to meet President Trump, undocumented migrants living in Ireland have penned a letter of support to all undocumented people in the US.
Campaigners, who are planning a candlelight rally on Dublin's Dame Street, say action for the undocumented here would 'speak louder than a bowl of shamrock in Washington'.
Aoife Murphy is from the Migrant Rights Centre Ireland, which supports the campaign.
"People in Ireland are very familiar with the issue of the undocumented Irish in America particularly, and a lot of families obviously with sons and daughters that they haven't seen for many, many years because they're undocumented in the US.
"But a lot of people might be unaware that they are actually thousands of undocumented migrants living in Ireland as well - many of whom have been living and working here for 10 years, 15 years - even longer".
