The Taoiseach Enda Kenny is travelling to Washington to mark events commemorating 1916.
He will join US Vice President Joe Biden to formally open the 'Ireland 100' festival at the John F Kennedy Center for the Performing Arts.
The event is a three-week long festival of Irish theatre, music, dance and literature.
It forms the centrepiece of more than 250 events commemorating the 1916 Rising in the United States.
On Wednesday, Mr Kenny will attend a number of official events to mark 1916 and the role of Irish-America in the Rising.
While he will also plant an Irish Oak tree on the grounds of the United States Congress at Capitol Hill, which is being billed as a very rare honour.
He will also visit the US Library of Congress to view items from its collections related to the Rising.
Later on Wednesday, the Taoiseach will attend a reception in the Statuary Hall of the US Capitol Building to celebrate Ireland-US relations.
Congressional leaders and representatives will attend the various events.
