Taoiseach Leo Varadkar, speaking at the Phoenix Park Hotel in Washington DC on Thursday evening, said politicians on both sides of the political divide in the United States had played a crucial role in the signing of the Good Friday Agreement.
Varadkar told the crowds gathered at the IrishCentral and AOH event that Irish Americans had "urged on" congress members and senators to play a role in Northern Irish affairs during the peace process.
"I think it's fair to say that, at critical junctures, the intervention of the US drove the peace process forward when few others could have," Varadkar said.
"Your influence is felt not just in Dublin, but also in Belfast, in London, and in Brussels. What America thinks about Ireland really does matter. Each time that a crisis has arisen, the support of the US has been sought and it has been given generously.
"Irish Americans have pushed their representatives in government to keep Northern Ireland on the agenda. I am very grateful to the congressmen and senators and their offices who take an interest in Ireland and make sure it is part of the US agenda."
Varadkar also discussed Ireland's economic ties with the US, stating that the two nations enjoyed a "mutually beneficial economic relationship".
"Today, Ireland and the United States enjoy a very close and mutually beneficial economic relationship, sustained by a two-way flow of trade and investment and enduring people-to-people ties.
"Ireland, for a long time, has provided US companies with a competitive base for their operations within the EU.
Varadkar said Ireland is now the ninth-biggest investor in the US, adding that 100,000 Americans worked in Irish firms based in the US.
"It's very much a two-way relationship."
The event, which marked the 25th anniversary of the historic agreement, also featured speeches from IrishCentral Chairman Liam Lynch and AOH President Danny O'Connell.
Lynch said it was an honor to host Varadkar at the event and praised the Taoiseach for his dedication to upholding the agreement.
O'Connell also paid tribute to Varadkar, adding that Irish-America continued to support the agreement 25 years on.
He said "The event was an opportunity to broaden our contact base on Capitol Hill. Many of the attendees were from Congressional offices that wouldn't normally be associated with Irish issues."