Speaking at a Democratic Party event in New York on Wednesday, US President Joe Biden said his visit to Northern Ireland was to ensure “the British didn't screw around,” according to a report from BBC in the US City.
Mr. Biden undertook a four-day visit to Ireland in April to mark 25 years since the Good Friday Agreement.
The trip also focused on the president's Irish ancestry with the majority of his time spent in the Republic of Ireland.
On Wednesday, Mr Biden said: I got to go back to Ireland for the, for the, the Irish Accords, to make sure they weren't, the Brits didn't screw around and Northern Ireland didn't walk away from their commitments.
Before setting off for his visit to Belfast, Mr Biden told reporters his priority was to keep the peace in Northern Ireland.
During his stay, commentators remarked on his limited contact with UK Prime Minister Rishi Sunak
The White House said both leaders reaffirmed their shared commitment to the Good Friday Agreement.
The 1998 deal brought an end to the Troubles - the decades-long violent conflict in Northern Ireland in which thousands of people were killed.
The president urged politicians to make a return to power-sharing during his speech at the Ulster University of Belfast campus on 12 April.
The Northern Ireland Executive collapsed last year when the Democratic Unionist Party (DUP) pulled out as part of a protest against post-Brexit trade rules for Northern Ireland.
A new Brexit deal for Northern Ireland, called the Windsor Framework, was formally adopted by the UK and EU in March, however, the DUP has yet to drop its protest.
In response to President Biden's remarks on Thursday, a Downing Street spokesperson said the UK priority was always protecting the Good Friday Agreement.
We are pleased between the UK and EU we have reached an agreement that works, they added.