Kevin O’Malley, who has just been appointed to the new role, said that he has been told to do “whatever he can” to help the process by President Barack Obama.
He has also been tasked with developing business and other relations between the US and Ireland.
Mr O’Malley was sworn into the office by US Vice President Joe Biden on Tuesday.
Mr O’Malley said he would be meeting up with all groups, north and south, to bring lasting peace.
“I’ve been asked to do whatever it is I can to connect up with all the appropriate parties and do what we can to arrive at a fair and just peace and to complete the process,” he told RTE News.
Mr O’Malley revealed his grandparents moved to America from Mayo around 100 years ago.
He added: “Growing up in St Louis, which has a strong Irish population, being Irish was important to us.”
He is the first US ambassador to Ireland since Dan Rooney who resigned in 2012.
However, Ambassador O’Malley said that the long period without an ambassador here did not reflect on the relationship between Ireland and the US.
The St Louis-based attorney, a devout Catholic, has more than 30 years experience in the legal profession.
Taoiseach Enda Kenny had raised the issue of the position of US ambassador to Ireland remaining vacant in his discussions with President Obama during his visit to Washington in March.
Mr O’Malley’s appointment had initially been met by some surprise within diplomatic circles as the attorney had a relatively minor profile.
However, President Obama has described Mr O’Malley as impressive and said he would lend “considerable” talent to the role.