David Nucifora, IRFU Performance Director, commented, "Peter's experience at this level and knowledge of the player group will provide important continuity ahead of June's World Rugby U20 Championship. Kieran will also add a wealth of experience to the coaching group.
"Nigel has done some fantastic work with the U20s over the past three years including reaching last year's U20 Championship final. We are delighted that Connacht have offered him the opportunity to further develop as a coach in a senior role with the provincial side.
"The coaching opportunity with the U20 squad is an important element in the IRFU's coach development pathway as it provides our Academy coaches with an outlet to develop and challenge themselves within the international game."
Ireland have been drawn in Pool B with Italy, New Zealand and Scotland and will play all three of their pool fixtures at the Kutaisi Stadium. Kutaisi is located 230km west of Tbilisi, the capital of Georgia.