Former US President Bill Clinton has claimed that being involved in the Northern Ireland peace process was one of the "greatest things" about being president. 

Bill Clinton spoke to former Taoiseach Bertie Ahern on Newstalk's "As I Remember It" podcast which celebrates the upcoming 25th anniversary of the Good Friday Agreement.

In episode eight of the nine-part series, Clinton reflected on the support the US gave to the Northern Ireland peace process and his controversial decision to grant a visa to Gerry Adams in 1994. 

"I promised, when I ran for President, that I would appoint a Special Envoy and that I would seriously consider a visa for Gerry Adams.

"Most people thought it was just politics with the Irish community in New York, but it was more than that.

"I realized that the size of the American diaspora and the level of investment we had in the North were so significant that we might be able to really make a difference."

Clinton said he turned down a visa for Adams during his first year in office, "but by the beginning of the second year, I was convinced that we had to do something like that to rope Sinn Fein because if they weren't really for some sort of agreement then we were never going to get it."

Clinton said both John Hume and Taoiseach Albert Reynolds told him he should grant the visa, "but a lot of Americans didn't want me to do it, including the Irish American Speaker of the House Tom Foley and, more importantly, the entire State Department."

Ultimately, Clinton "knew that we had to do something to get this process off the ground."

"It was rocky in the beginning," Clinton recalled, "a lot of people thought I lost my mind when I did it."

Elsewhere in the podcast episode, Clinton also recalled how his late-night telephone calls during the last 48 hours of the Good Friday Agreement negotiations helped push David Trimble and Ulster Unionists into signing the agreement. 

Clinton told Ahern that credit for the agreement must go to the leaders directly involved in the negotiations. 

"If you look at the Irish problem in the context of what else has happened in the world in the last 20 years, you might think it's a miracle that the peace agreement has held at all," Clinton told Ahern. 

"I love it when people give me some credit for it, but the truth is I think the ultimate credit goes to the leaders like you and Tony [Blair] and the people who came before you - and to the people who just decided they needed to stop killing each other." 

Clinton also paid tribute to the Irish American community for supporting him during his impeachment trial in 1998.

"I remember 800 Irish people showed up on the South Lawn of the White House in 1998 when they were trying to run me out of office and said, ‘you can't do this! We have to do the peace here'," Clinton told Ahern.