Boston Cardinal Sean O'Malley has said he will boycott the Boston College graduation because Taoiseach Enda Kenny will be addressing the graduates.
Cardinal O'Malley said he will not attend because he says the Taoiseach is "aggressively promoting abortion legislation".
The Taoiseach is due to address graduates at the 137th annual Boston College Commencement Exercises on 20 May.
Cardinal O Malley said: "The Catholic Bishops of the United States have asked that Catholic institutions not honor government officials or politicians who promote abortion with their laws and policies.
"I am sure that the invitation was made in good faith, long before it came to the attention of the leadership of Boston College that Mr Kenny is aggressively promoting abortion legislation.
"Since the university has not withdrawn the invitation and because the Taoiseach has not seen fit to decline, I shall not attend the graduation."