Northern Ireland's "unjust" abortion law should reflect the majority's desire to protect the lives of the unborn, the Catholic church said.
A major change liberalising access to the procedure was introduced in March.
Ireland's Archbishop, Eamon Martin, urged lawmakers at Stormont to urgently debate the matter.
He and other bishops said: "Insofar as they exceed the requirements of the Northern Ireland Act 2019, we urge you to take steps to formulate new regulations that will reflect more fully the will of a significant majority of the people in this jurisdiction to protect the lives of mothers and their unborn children."
The regulations will allow terminations on request in Northern Ireland for the first 12 weeks of pregnancy and up to 24 weeks in case of a risk of injury to the physical or mental health of the pregnant woman or girl.
Abortion will also be available in cases of severe and fatal foetal anomalies, with no gestational limit.
MPs at Westminster legislated for the change while the Stormont Assembly was not sitting following a three-year row between powersharing partners Sinn Fein and the DUP which was resolved in January.
The bishops told Stormont Assembly members: "While we regard this to be an unjust law, which was imposed without the consent of the people of Northern Ireland, we are morally obliged, wherever possible, to do all we can to save the lives of unborn children, which could be lost through abortion, and to protect mothers from the pressures they might experience at the time of an unplanned pregnancy.
"We trust that you recognise this to be an obligation we all share as concerned citizens and public representatives."
Stormont's two main parties are at opposite ends of the debate over abortion.
The DUP has previously prevented legal change to its prohibition in almost all circumstances in Northern Ireland.
Discussions at the divided ministerial Executive are ongoing on the exact shape of provision.
Women are able to travel to Great Britain for procedures.
Journeys have been complicated by restrictions designed to limit the spread of the coronavirus.