The nation's Roman Catholic bishops told President Bush it could be immoral for the United States to go to war with Iraq, warning the president to exhaust all possible peaceful solutions to the Persian Gulf crisis.

At the opening session of the four-day annual National Conference of Catholic Bishops meeting, the 300 prelates voted overwhelmingly Monday to endorse a letter to Secretary of State James Baker sent last week by Los Angeles Bishop Roger Mahony, head of the conference's international policy committee.But a number of bishops called for a stronger statement including a statement telling Catholic military personnel they have a right to be "selective conscientious objectors" to any U.S.-initiated war with Iraq.

Under the prodding of a group of peace-oriented bishops, led by Bishop Michael Kenny of Juneau, Alaska, and Archbishop Francis Hurley of Anchorage, Alaska, the bishops agreed to debate an even stronger condemnation of Bush administration policy in a closed session on Wednesday.

The bishops' policy on the crisis has been based on a series of principles, including the "clear need to resist (Iraqi) aggression."

"We cannot permit nations to simply overwhelm others by brutal use of force," Mahony told Baker.

But at the same time the bishops said there is an "imperative to seek a peaceful resolution of the crisis and pursue legitimate objectives by non-violent diplomatic means."

The bishops said that even right of self-defense and the need to repel aggression "is restricted and governed by a series of moral principles."