Billy Walsh has resigned as Ireland head coach after overseeing a golden era for the sport.
Walsh had been in contract negotiations with the IABA but on Monday he stepped down after 12 years in the post to take up a new position in the United States.
"Regrettably the IABA have not made it possible for me to continue on in the role," said Walsh.
Ireland won Olympic, World and European gold medals at amateur level during Walsh's successful period as coach.
Belfast pair Paddy Barnes and Michael Conlan were among the many Irish boxers to blossom under the guidance of Walsh.
"Since February of this year I have been engaged in a process with the IABA to secure my future as Head Coach with the High Performance Unit and senior team," added Walsh.
"A protracted process that went on for eight months included numerous high level meetings that resulted in various proposals.
"In August a fair proposal was developed under the auspices of the Irish Sports Council (ISC) that was acceptable and fair but then not subsequently ratified by IABA.
"I was hopeful in recent weeks that a final proposal arising out of an approach in late September by the IABA would lead to a successful conclusion but unfortunately it didn't."
"I am greatly looking forward to the opportunities ahead in bringing my expertise and experience to the USA Women's Team as they prepare for success in Rio and beyond."
Sport Ireland 'extremely disappointed'
In a statement, Sport Ireland said it was "extremely disappointed" to learn that Walsh had decided to step down, adding that it had "made every effort within its authority to resolve this issue".
"Billy Walsh has overseen an unprecedented period of success in Irish Boxing including, most recently, at the World Senior Championships. Sport Ireland is deeply appreciative of his contribution and wishes him well in his future. The USA's gain is Ireland's loss," read the statement.
"As the legal employer it was a matter for the IABA to resolve and it insisted on its autonomy to negotiate with their Head Coach. Sport Ireland was unequivocal in its desire to keep Billy Walsh in Irish sport and communicated clearly to the IABA that every support would be provided in order to retain him at the High Performance Unit of the IABA.
"This position was strongly supported by the Minister for Sport, Michael Ring, who met with representatives of the IABA on three occasions to facilitate an agreement and by Sport Ireland who met the IABA on several occasions."
Fergal Carruth, Chief Executive of the IABA said: "The IABA has been in discussions with Billy following his approach to the organisation to seek improved terms and conditions after he stated that he had received an offer from USA Boxing.
"The IABA is deeply disappointed not to retain his valued services, and for the avoidance of any doubt, the IABA has done its utmost to retain Billy Walsh as Head Coach. However, Billy himself has made the decision to resign and take up a position with USA Boxing, and we wish him every success with this."