Enda Kenny says getting legalised immigration status for Irish people in America is an "absolute priority" this week.
The Taoiseach made the comments as he began a week-long trip to the United States, culminating in a meeting with US President Donald Trump.
Today Mr Kenny attends the Philadelphia St Patrick's parade.
He will also visit Boston, Rhode Island and New York.
From Philadelphia, our political correspondent Gavan Reilly reports: