Key leaders in the peace process have been celebrating 20 years since the Good Friday Agreement was signed.
Leo Varadkar gave a keynote address at an event at the Library of Congress in Washington DC.
As key figures in the peace process gathered on Capitol Hill there was a sense of much done, more to do.
Former US President Bill Clinton remembered the joy that came with a deal:
"The day the Good Friday Agreement was reached and signed was one of the happiest days of my presidency," he said.
The political impasse in Northern Ireland loomed large over the event, with former Sinn Féin leader Gerry Adams conceding it is unlikely to end soon:
"The powersharing government in the all Ireland political architecture may not be restored in the medium term," Adams said.
Leo Varadkar described the lack of an executive as corrosive, and said there needs to be a return to talks:
"The period after Easter should see a redoubled effort on the part of both governments and all of the parties in Northern Ireland to seek agreement on the restorations of the institutions," the Taoiseach said.
The Taoiseach's visit to the US takes a turn today to focus on commerce, with a number of events planned.