The White House is the focus of Irish celebrations
Deputy First Minister Martin McGuinness is leading a delegation to the United States for St Patrick's Day celebrations at the White House.
First Minister Ian Paisley is not attending but junior minister Jeffrey Donaldson is going in his place.
Irish Taoiseach Bertie Ahern will participate in traditional shamrock ceremony with President George Bush.
The leaders will hold talks and then meet NI Secretary Shaun Woodward and other political and business delegates.
The White House said the shamrock ceremony symbolises the "deep cultural roots and close ties of friendship" between the United States and Ireland.
Mr Ahern told the Dail on Wednesday that the celebrations surrounding the national holiday on 17 March
provides a "framework to showcase modern Ireland all over the
He added: "It is used by us as a marketing opportunity."
Meanwhile, Mayor of New York Michael Bloomberg has confirmed he will attend a major economic investment conference in Belfast in May.