Spending 3 1/2 years helping Northern Ireland politicians to make a peace agreement has awakened George Mitchell's interest in his own Irish roots. But he wonders when he will ever get the time to explore them.

He and his wife, Heather, hope to spend a summer in Ireland and Scotland tracing their ancestors. He is a Kilroy from somewhere in the west of Ireland whose grandfather emigrated to Boston, and she is a MacLachlan from Scotland whose family emigrated to Canada.

The urge to delve into his Irishness has become stronger since the negotiations ended a year ago with the Belfast Agreement. "At the time I was so darn busy I did not really give much thought to it. Although I was in Ireland almost every week for a few years I hardly ever saw or did anything other than go to Stormont, work long hours and go back home."

While he has been showered with honours for his role in chairing the talks, the former US Senate majority leader has not exactly fond memories of that time he calls "the longest, most difficult years of my life." He deliberately did not keep a diary and his book "is not a history of the negotiations but an account of my personal experiences".

Sitting in the offices of his legal firm, Verner Liipfert, in downtown Washington, Mitchell says: "It is easy to look back and mentally glamorise and romanticise what was happening, but it was very tedious and difficult and for the most part discouraging."

He seriously thought about pulling out in the spring of 1997 after a year of "very little happening" and with no IRA ceasefire. For the first time he spoke to someone other than his wife about his discouragement.

He told Sandy Berger, national security adviser to President Clinton, "about the possibility of my leaving but I decided to stay. It was very difficult".

The pace of work and travel was becoming almost unbearable. He would leave Belfast on a Thursday and work at his legal job in Washington on Friday and Saturday. Sunday he would fly back to Belfast after time with his wife in New York and another week would start.

There were personal sorrows like the death of his older brother, Robbie, to whom he had been very close, and Heather's miscarriage.

Does he not feel that the Northern Irish politicians are too mollycoddled by having their hands held by outsiders to get them to agree on their own affairs?

Mitchell thinks about this for a while.

"One reason I have expressed reluctance to return is to encourage them to learn to work together and solve their problems by themselves. I think it is inevitable that there is a weaning process that has to occur."

He believes that it is "not inappropriate" that the British and Irish heads of government should be involved, such as at this week's negotiations, but "direct US involvement is another thing". While Mitchell is now attached to Northern Ireland and its people, "it is not helpful that people keep suggesting that I come back because it can create recalcitrance on the part of the participants. If they think negotiations are not really going to begin on each issue until I or someone else comes in from the outside, they're much less likely to be forthcoming and to be willing to compromise among themselves. I think that attitude has to change."

George Mitchell nearly was not there to preside over the successful ending to the Belfast Agreement. He came within a hair's breadth of becoming President Clinton's Secretary of State for his second term, in January 1997. Mitchell was reported to have "bonded" well with the President when he coached him earlier for his two election debates with his Republican challenger, Senator Bob Dole.

Mitchell was asked to meet the President as part of his deliberations on his choice for the top post in his new Administration.

"I spent more than three hours at the White House and talked at great length with the President."

Then Mitchell was told by senior White House staff that the list had been "narrowed down to two, and I was one". The other was the US ambassador to the United Nations, Madeleine Albright.

When she got the call, Mitchell says he had mixed feelings. But "things have a way of working out". He was pleased at being able to stay with the peace talks and "at least contribute to getting an agreement on Good Friday".

Was the fact that Madeleine Albright was pushed hard by the women's organisations and reportedly by Hillary Clinton herself for the top job a factor? Mitchell shrugs. "I have been told that." But he adds with a smile that only one person really knows.

What of the future? Will he remain with Verner Liipfert, now the top lobbying firm in Washington? "I don't have any immediate plans to take on any new activities. I'm cutting back on them. I'm so darn busy."

He, Heather and their two-year-old son, Andrew, are going to travel more together. They will be with him when he goes to Belfast this summer to be inaugurated as Chancellor of Queen's University.

Making Peace by George Mitchell is published by Heinemann, price £18 in UK.