The organisers of The Gathering have defended the initiative after actor Gabriel Bryne described it as a “scam”.
Project Director of The Gathering Ireland Jim Miley said Mr Byrne’s comments were "just one man’s opinion".
Speaking on RTÉ’s Morning Ireland, Mr Miley said it would be a mistake to paint the diaspora as one unit.
"The diaspora and The Gathering are bigger than any one man, be it Gabriel Byrne or otherwise. In fact, it's bigger than our project.”
He pointed out that several other well-known Irish-Americans, such as Jean Butler and Fionnula Flanagan, were warmly endorsing The Gathering.
Mr Miley added that Ireland has never reached out before in a systematic way to the diaspora in the way The Gathering is doing.
The whole purpose of The Gathering, he said, was "thinking very deeply about our emigrants", which he hoped would "lay a little foundation stone" for a new way of reaching out to people living overseas.
Taoiseach Enda Kenny also said he disagreed with Mr Byrne.
Speaking in the Dáil, Mr Kenny said that the US diaspora represents more than half of our global diaspora.
Describing The Gathering as a “very credible” initiative, he said it was not just about raising money but was also about providing a really good experience for visitors.
Mr Byrne, who previously served as a cultural ambassador, said many who left Ireland for the US feel abandoned by the Government.
The Dublin native claimed that the bridge between Ireland and its diaspora is broken.
He also said Irish-Americans are not receptive to being "shaken down" for money.
Speaking on Today FM yesterday, Mr Byrne said Taoiseach Enda Kenny’s speech launching the initiative was "slightly offensive".
"People are sick to death of being asked to help out in what they regard as a scam," he said.
"I wish The Gathering the very best of luck but they have to understand that the bridge between the diaspora and the people is broken and I tried to fix that for two years and it’s still broken.... Most people don’t give a s**t about the diaspora [in Ireland] except to shake them down for a few quid."
He added: "The diaspora has a very powerful spiritual connection to the island of Ireland.
"I remember when I was growing up in Dublin those buses would pull up and those people in Burberry coats would be laughed at because they’d say 'here come the Yanks looking for their roots’.
"Well, as far as I’m concerned one of the most sacred things you can do is look for your roots."